I like Emera! I dunno what your 2yo's name is, so I can't say if it would sound too matchy when you introduce them together, but honestly that wouldn't bother me much....they are in all likelihood going to be associated closely for only the first 18 years of their lives, yk? My parents named my next-older sister Susan, so we were Susan-and-Sarah all our childhood, and I always had teachers (who had had her in class only 2 years before) call me by her name, etc....and even though it was mildly annoying at the time, it doesn't even register now that we are adults, living utterly separate lives.
Plus, I think lots of parents try to name their kids names that sound cohesive together, yk?
I also LOVE Ivy, and IMO, it is adorable for a little girl, spunky for a bigger girl, and becomes more and more elegant and classic for a young lady/woman/mother/grandmother. It just "grows" very well!
As for fitting your last name, I don't think it's too much. I wouldn't pair it with another "v" sound in the middle name, but I think it's fine.
ETA: the only possible problem I can foresee with Emera is a potential for teasing by pairing it with "enema". Probably not a huge factor, since it's not a word most kids are familiar with.....