Emily nn Emmy!
I know Emily is very popular, but I find it to be timeless and elegant. Liliana / Lillian / Lily are a bit too trendy for me. Emily Smith is quite a common name, if that is not a concern to you then go for it! I'd suggest a more unique middle name to balance it out.
Also, Emily is perfect with Charlotte and Sophie.
Liliana is a name that I love, it's high up on my own list but lately I've been having second thoughts to whether I actually do like it better than Lillian. I've decided that although Liliana is more uncommon and quite "frilly" as some people say, I do like it more. Liliana Rae is my standard combo but I am also looking to change, I also like: Liliana Eve, Liliana Skye, Liliana Brooke, Liliana Emma, Liliana Wren, Liliana Kay :)
Lillian! I think it's beautiful and goes well with your other names.
I like Emily best with Charlie and Sophie.
Sure, Emily has been over-done in the past, but right now, there are little Lily's everywhere! She'd be more likely to be one of several Lily's in her class that one of several Emily's.
That being said, I think that Lillian is a beautiful name, and goes very well with her big sisters' names. I think Lilliana is just too frilly and fussy.