I love all of them, except for Elizabeth.
I know that Elizabeth is a classic with many namesakes, but I can't help but think of the royal family and I'm not a huge fan of theirs even though they are sort of interesting from a historical point of view. I think of the Queen waving and of Cate Blanchett in the "Elizabeth" movie and both are sort of weird associations. It's also kind of bland and boring and it comes with so many nicknames that her peers might end up calling her something you dislike (or she herself might choose a nickname that you dislike). For example, you like Liz but she wants to be Betsy. I am just tired of it and all of the nicknames that all sort of feel dated (Betty to the 30s, Lizzie to the 80s, Libby to the 90s etc.). So this is my least favourite, but still a solid choice, of course.
I love the others so it's hard to choose between them.
Annabel - is a long time favourite and I love this spelling. It makes me think of the poem by Edgar Allan Poe (Annabel Lee). Classic, lovely name and underused (Annabelle was popular a few years ago but fell rapidly, I guess because of the "Annabelle" horror films). You can't go wrong with Annabel.
Eleanor - is so beautiful, elegant and classic. I love it. Only negative is that Ell-names are so popular (Ella, Ellie, Ellen) and falling so might seem a bit tired after a while and she could end up as yet another Ellie. Still lovely.
Isabel - I love this too but I prefer Isabelle. I think this is the most common one if you are in England or Wales (all spellings combined). I would say that this was a bit overused. I still like it. The many different spellings are a bit annoying, because all of them were sort of common (Isabel, Isobel, Isabelle).
I would pick Eleanor or Annabel. I genuinely couldn't decide because I love them both so much. Maybe Annabel right now but could be Eleanor in a few hours.
Eleanor Annabel is a lovely combo.