I love the nn [name]Millie[/name] and the full name [name]Millicent[/name] has grown on me. However, my name is [name]Melissa[/name]. I already have 2 daughters so I think it might be odd to give a third (hypothetical) daughter a name so close to mine. What do you think?
Also, how else could I get to [name]Millie[/name]? Thanks!
I do find [name]Millicent[/name] a little overly close to [name]Melissa[/name], especially knowing the connection between [name]Millicent[/name] and [name]Melisande[/name], which is even more similar.
Other ways to get to [name]Millie[/name] (which is lovely, by the way):
[name]Camilla[/name]
[name]Carmella[/name] (maybe a tiny bit of a stretch; [name]Mellie[/name]'s more intuitive, but I think it could work)
[name]Emily[/name]
[name]Ludmila[/name]
Good luck! 
I know a [name]Millie[/name] who’s full name is [name]Amelia[/name]. I didn’t know her full name for a long time because everyone just called her [name]Millie[/name]. I think [name]Millie[/name] is adorable.
You’ve received some great suggestions already, but I wanted to add [name]Milena[/name]. There’s [name]Mildred[/name], but that might be too “old” for many tastes. I love the suggestion of [name]Camilla[/name]/[name]Camille[/name]. Did someone say [name]Camelia[/name]?
I think the [name]Mel[/name]/[name]Mil[/name] beginnings more similar than anything, really. I wouldn’t find [name]Amelia[/name] nn [name]Millie[/name] any less matchy than [name]Millicent[/name] nn [name]Millie[/name]. It’s still [name]Melissa[/name] and [name]Millie[/name]. I have to say, though, I do prefer [name]Amelia[/name]/[name]Emilia[/name] nn [name]Millie[/name]. I’m not ready for [name]Millicent[/name]'s revival yet.
My best friend was an [name]Amelie[/name] nn [name]Millie[/name], I think that’s lovely. A few other options:
[name]Matilda[/name] “[name]Millie[/name]”
[name]Romilly[/name] “[name]Millie[/name]”
[name]Emmeline[/name] “[name]Millie[/name]”
I like the suggestions of [name]Camellia[/name] and [name]Milena[/name], too. With your girls, I like something along the lines of [name]Amelia[/name] with [name]Laurel[/name], but I think something like [name]Matilda[/name] fits better with [name]Vita[/name], but I think something like [name]Romilly[/name] might blend the styles of [name]Vita[/name]'s and [name]Laurel[/name]'s names best. I think it just depends on what you’re going for. [name]Romilly[/name], [name]Camellia[/name], [name]Milena[/name], and [name]Emmeline[/name] are the ones unlisted on the SSA list, though, if that still matters to you (which I assume it does!).
I think [name]Millie[/name]'s adorable, btw.
Good luck!
I second [name]Amelia[/name]. I know a little girl named [name]Amelia[/name] that goes by [name]Millie[/name]. [name]Romilly[/name] is also a beautiful name, but I’m not sure it’s your style.
Suggestions:
[name]Amelie[/name]
[name]Emilie[/name]
[name]Malina[/name]
[name]Michelle[/name]
[name]Melina[/name]
Emilina
[name]Matilda[/name]
Maleaya
I love [name]Millie[/name] sooo much!! I tried to find a way to use it too. I like [name]Millicent[/name] but my name is also [name]Melissa[/name]! I kind of thought it was neat since my grandfather always called me [name]Millicent[/name]. I don’t think it’s too close personally…i think it could work. But another name I found that can use nn [name]Millie[/name] is [name]Matilda[/name] which I also adore!
This is going to sound dumb (maybe it is!) but my sister shares her first initial with my mom and I don’t and it was a minor source of some sibling rivalry growing up.
just something to consider.
Thanks everyone! [name]Amelie[/name] is on my list and for some odd reason I never thought of [name]Millie[/name] as a nn for this, ha! DH loves [name]Amelia[/name] but its too popular for my taste.
@ash, thank you for the well thought out answer and great memory as always! I realize my girls names are stylistically a bit different so, yes, finding something to help blend the styles will be a priority. I love a good challenge 
@misshoppy, not dumb at all!! A really good point that makes some sense to me. Thanks for pointing out a potential pitfall.
[name]Amelie[/name] is gorgeous! [name]Millie[/name] as a nickname would be cute.
Best of luck!