[name_f]Amelia[/name_f] nn [name_f]Lily[/name_f] - I like [name_f]Amelia[/name_f] and I love [name_f]Lily[/name_f], but apart from them both having L sounds, I don’t think they’re particularly similar at all and so I think [name_f]Lily[/name_f] would be a bit of a stretch. Maybe [name_f]Millie[/name_f] would work instead?
[name_f]Lily[/name_f] - I think [name_f]Lily[/name_f] is a beautiful standalone name, and I think it could be a sister for [name_f]Amelia[/name_f] or even a middle name for it. I’m pretty sure there was a British X-factor contestant a while ago who was called [name_f]Amelia[/name_f] [name_f]Lily[/name_f], and I think it makes a very pretty and usable combo.
[name_f]Rosalie[/name_f] nn [name_f]Rosie[/name_f] - [name_f]Rosalie[/name_f] doesn’t seem too old-fashioned or at all pretentious to me, but then again, I possibly have rather pretentious taste 
[name_f]Rosie[/name_f] is a cute nickname, but I prefer it as a nickname for something else, as I’m not sure if a forty-year old would still want to be a [name_f]Rosie[/name_f]. If you’re not keen on [name_f]Rosalie[/name_f], you could use [name_f]Rosie[/name_f] as a nickname for simple [name_f]Rose[/name_f] or [name_f]Rosa[/name_f], [name_f]Rosamund[/name_f], [name_f]Rosaline[/name_f], Rosabel, [name_f]Rosemary[/name_f] etc. There are lots of options!
[name_f]Isabelle[/name_f] or [name_f]Isabel[/name_f] nn [name_f]Ellie[/name_f] - I love [name_f]Isabelle[/name_f]/[name_f]Isabel[/name_f], although my personal favourite spelling is [name_f]Isobel[/name_f]. I think [name_f]Ellie[/name_f] works as a nickname, but it’s a very common nickname for lots of other names, and so it will be one you’ll encounter often and people might assume your daughter is called [name_f]Eleanor[/name_f] or something. I personally find [name_u]Issy[/name_u] very cute, but other choices you might like include [name_f]Belle[/name_f]/[name_f]Bella[/name_f] (although I assume you’ve thought of this), [name_f]Ibby[/name_f], Ibsy, [name_f]Saba[/name_f]/[name_f]Sabella[/name_f], [name_u]Isa[/name_u]/[name_u]Issa[/name_u], Zabby/Sabby, or if you use the [name_f]Isobel[/name_f] spelling you can even get away with [name_f]Zoe[/name_f] I think.
[name_f]Imogen[/name_f] nn Immi - I adore [name_f]Imogen[/name_f], it’s probably my favourite of your names (tied with [name_f]Ottilie[/name_f]) so I definitely think it’s pretty enough. [name_f]Imogen[/name_f] nn Immi is lovely, although I prefer the [name_f]Immy[/name_f] spelling. If you like the ‘L’ sound you could always put it in the middle - [name_f]Imogen[/name_f] [name_f]Lily[/name_f] or [name_f]Imogen[/name_f] [name_f]Ottilie[/name_f] would be gorgeous.
[name_f]Eleanor[/name_f] nn [name_f]Ellie[/name_f] - I think [name_f]Eleanor[/name_f] is a very strong name, but it’s not one I ever describe as pretty, but I don’t think all names have to be ‘pretty’. [name_f]Eleanor[/name_f] is beautiful and elegant and a strong, feminine classic. For me, [name_f]Ellie[/name_f] takes away from [name_f]Eleanor[/name_f]'s strength and adult feeling, as it feels very juvenile and popular. I prefer the slightly more grown up [name_f]Ella[/name_f] or [name_f]Elle[/name_f].
[name_f]Ivy[/name_f] - it’s short but sweet, but no there isn’t really a nickname. If you did something like [name_f]Imogen[/name_f] [name_f]Violet[/name_f] you could use it as a nickname though as you’d have the I and V initials
[name_f]Marnie[/name_f] - I think this is sassy and funky, if a little old fashioned, but I always find the sound a bit whiny. I also think it works better as a nickname. Maybe [name_f]Marina[/name_f] nn [name_f]Marnie[/name_f] or [name_f]Hermione[/name_f] nn [name_f]Marnie[/name_f] would work?
[name_f]Martha[/name_f] - it’s a little old-fashioned, but perfectly usable. There’s no obvious nickname but I think [name_f]Mari[/name_f] or Arti or [name_f]Martie[/name_f] or [name_u]Mattie[/name_u] could work, and if you used a nickname with an N beginning you might even be able to get away with [name_f]Martha[/name_f] nn [name_f]Marnie[/name_f]
[name_f]Ottilie[/name_f] nn [name_f]Lily[/name_f] - I adore [name_f]Ottilie[/name_f], and I don’t really think it needs a nickname but I think [name_f]Lily[/name_f] would work here, as the sounds are much more obvious than in [name_f]Amelia[/name_f]. Otherwise I know Ottilies nn Otti, and I think Otter would be cute as a little girl, and then [name_f]Tillie[/name_f].
Also would [name_f]Amelia[/name_f] and [name_f]Eleanor[/name_f] be acceptable as sisters if their nicknames are [name_f]Lily[/name_f] and [name_f]Ellie[/name_f]? I think [name_f]Lily[/name_f] and [name_f]Ellie[/name_f] work as nicknames for sisters, but I can’t get behind [name_f]Amelia[/name_f] nn [name_f]Lily[/name_f], as the names just sound so different to me.
What about [name_f]Lily[/name_f] and [name_f]Rosie[/name_f]/[name_f]Rosie[/name_f] and [name_f]Ivy[/name_f]/[name_f]Lily[/name_f] and [name_f]Ivy[/name_f] as sisters - is both being plant names unacceptable? I think it’s quite common for sisters to all have plant/flower names, so I wouldn’t worry about this. If you’re going to name one child [name_f]Ivy[/name_f] though, I wouldn’t use a flowing, long name like [name_f]Amelia[/name_f] for the other though
