This is our first, and we don’t know the gender yet, but I believe it will be a girl. Either way it’s good to be prepared, right? For the longest time, I’ve loved the name [name_u]Wren[/name_u]. It’s simple and sweet. But our last name is [name_m]McEwen[/name_m] (muhk-yoo-uhn). [name_u]Wren[/name_u] [name_m]McEwen[/name_m] isn’t the worst sounding combo in the world, but I can’t think of a single middle name that flows. And with our last name, [name_u]Wren[/name_u] sounds a little…clipped, if that makes sense. If anyone has suggestions I would really appreciate it. And feel free to be candid with me. If it doesn’t work it doesn’t work 
I actually think it might be your last name rather than [name_u]Wren[/name_u] that makes finding a middle name that flows well difficult. It’s a nice name, but there are a lot of distinct sounds to get your mouth around. I think [name_u]Wren[/name_u] works well enough, but a simple middle might flow best. A few ideas:
[name_u]Wren[/name_u] [name_f]Marie[/name_f] (I actually really like this. To my ear, the repeated M helps the flow.)
[name_u]Wren[/name_u] [name_f]Catriona[/name_f]/[name_f]Katrina[/name_f]
[name_u]Wren[/name_u] [name_f]Patricia[/name_f]
[name_u]Wren[/name_u] [name_f]Matilda[/name_f]
[name_u]Wren[/name_u] [name_f]Christina[/name_f]
[name_u]Wren[/name_u] [name_f]Marissa[/name_f]
[name_u]Wren[/name_u] [name_f]Melissa[/name_f]
I love [name_u]Wren[/name_u]! I have to say that I don’t absolutely adore the fn/ln combination, but it definitely sounds better than it looks! So I don’t think it would be an issue at all. I would definitely stay away from names that have w, r, e, or n anywhere prominent, as that would just add confusion. Something feminine maybe, probably two or three syllables like [name_f]Lily[/name_f] or something? I don’t really know what your other taste is, so it’s hard to go just off [name_u]Wren[/name_u].
But here are some thoughts:
[name_u]Wren[/name_u] [name_f]Lily[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Hazel[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Alice[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Olivia[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Ava[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Isabel[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Abigail[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Victoria[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Lucy[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Alexa[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Josephine[/name_f] [name_m]McEwen[/name_m]
[name_u]Wren[/name_u] [name_f]Juliette[/name_f] [name_m]McEwen[/name_m]
From that list, I love [name_u]Wren[/name_u] [name_f]Lily[/name_f] and [name_u]Wren[/name_u] [name_f]Juliette[/name_f]. Good luck 
I really like [name_u]Wren[/name_u] [name_f]Isabelle[/name_f], but with the last name I’m not sure. Some other thoughts:
[name_u]Wren[/name_u] [name_f]Willow[/name_f]
[name_u]Wren[/name_u] [name_f]Luna[/name_f]
[name_u]Wren[/name_u] [name_f]Violet[/name_f]
[name_u]Wren[/name_u] [name_f]Flora[/name_f]
[name_u]Wren[/name_u] [name_u]Ruby[/name_u]
[name_u]Wren[/name_u] [name_m]Wyatt[/name_m]
[name_u]Wren[/name_u] is lovely. Your surname does seem to be a tricky one to pair names with. I don’t think [name_u]Wren[/name_u] sounds that bad with it though.
For middle names, what about:
[name_u]Wren[/name_u] [name_f]Elizabeth[/name_f] M
[name_u]Wren[/name_u] [name_f]Josephine[/name_f] M
[name_u]Wren[/name_u] [name_f]Amelie[/name_f] M
[name_u]Wren[/name_u] [name_f]Penelope[/name_f] M
[name_u]Wren[/name_u] [name_f]Emmeline[/name_f] M
[name_u]Wren[/name_u] [name_f]Genevieve[/name_f] M
[name_u]Wren[/name_u] [name_f]Evangeline[/name_f] M
[name_u]Wren[/name_u] [name_f]Theodosia[/name_f] M
[name_u]Wren[/name_u] [name_f]Caroline[/name_f] M
I think something longer works well. I know your surname is 3 syllables but it think using a middle name with different syllable stress works and creates a balance between it and the 1 syllable [name_u]Wren[/name_u].
I also think switching and using [name_u]Wren[/name_u] in the middle name could work;
[name_f]Amelia[/name_f] [name_u]Wren[/name_u] M
[name_f]Felicity[/name_f] [name_u]Wren[/name_u] M
[name_f]Lilith[/name_f] [name_u]Wren[/name_u] M
[name_f]Orla[/name_f] [name_u]Wren[/name_u] M
[name_f]Xanthe[/name_f] [name_u]Wren[/name_u] M
I think [name_f]Felicity[/name_f] [name_u]Wren[/name_u] Mc**** is absolutely beautiful.
I’ve been seeing the name [name_f]Wrenley[/name_f] on pinterest a lot. Would that work
[name_u]Wren[/name_u] [name_f]Cecilia[/name_f] (my favorite)
[name_u]Wren[/name_u] [name_f]Eliza[/name_f]
[name_u]Wren[/name_u] [name_f]Felicity[/name_f]
[name_u]Wren[/name_u] [name_f]Louisa[/name_f]
[name_u]Wren[/name_u] [name_f]Philippa[/name_f]
[name_u]Wren[/name_u] [name_f]Susannah[/name_f]
[name_u]Wren[/name_u] [name_f]Lilia[/name_f]
[name_u]Wren[/name_u] [name_u]Evelyn[/name_u]
[name_u]Wren[/name_u] [name_f]Marie[/name_f] (I second this, it flows beautifully)
[name_u]Wren[/name_u] [name_f]Margot[/name_f]
[name_u]Wren[/name_u] [name_f]Elizabeth[/name_f] (a classic middle name choice but I think it’s flows very well)
[name_u]Wren[/name_u] [name_f]Amelia[/name_f]
[name_u]Wren[/name_u] [name_f]Emilie[/name_f]
I think something with a prominent M sound would work well with your surname.
If you are really worried about the flow, you could switch and put her middle name as [name_u]Wren[/name_u] and call her by her middle name. I often think this causes more problems than it solves though! Personally, I think [name_u]Wren[/name_u] [name_m]McEwan[/name_m] flows just fine. [name_f]Hope[/name_f] this helps
As pp have mentioned, its not [name_u]Wren[/name_u] that is the problem, its the last name. I think no matter what name you pick the last name is still a tongue twist. I love the simplicity of [name_u]Wren[/name_u] and I think something short and sweet will help with the flow. I also think anything with a heavy U sound, such as [name_f]Luna[/name_f]/[name_f]Lucy[/name_f] is out.
[name_u]Wren[/name_u] [name_f]Elise[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Sophie[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Isla[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Lila[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Ivy[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Esme[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Eve[/name_f]/[name_f]Eva[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Sylvie[/name_f]/[name_f]Sylvia[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Elena[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Violet[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Audrey[/name_f] McE…
[name_u]Wren[/name_u] [name_f]Sophie[/name_f], [name_u]Wren[/name_u] [name_f]Isla[/name_f] and [name_u]Wren[/name_u] [name_f]Ivy[/name_f] are my favorites.
As someone said I really like [name_u]Wren[/name_u] [name_f]Marie[/name_f]
I see it’s already been suggested but [name_u]Wren[/name_u] [name_f]Susannah[/name_f] is on my own long-list. I think it sounds great with your surname! I think you need something long, vowel-rich and uncomplicated.
Other ideas:
[name_u]Wren[/name_u] [name_f]Emilia[/name_f]
[name_u]Wren[/name_u] [name_f]Isabella[/name_f]
[name_u]Wren[/name_u] [name_f]Sophia[/name_f]
[name_u]Wren[/name_u] [name_f]Viola[/name_f]
[name_u]Wren[/name_u] [name_f]Eliza[/name_f]
[name_u]Wren[/name_u] [name_f]Alicia[/name_f]
[name_u]Wren[/name_u] [name_f]Adeline[/name_f]
[name_u]Wren[/name_u] [name_f]Josephine[/name_f]
[name_u]Wren[/name_u] [name_f]Jessamy[/name_f]
[name_u]Wren[/name_u] [name_f]Marguerite[/name_f]