Re: Elizabeth and Georgiana?
I don't think anything can be too much when alongside Elizabeth. It's so common and plain for a lot of people. I think those would be beautiful names for sisters. Both names are gorgeous. I like them both as first names, though I think Georgiana makes a nice middle name too.
I think they would be alright with your son's name. Georgiana alone not quite as much, but if there was an Elizabeth first it kind of ties it in.