I prefer [name]Maia[/name] just because [name]Serena[/name] reminds me a little too much of the TV show Gossip Girl. They both sound nice, though.
[name]Maia[/name] [name]Annabelle[/name] sounds okay, but I don’t love the flow of it. I do like that it has significance to you.
Here are some other ideas:
[name]Maia[/name] [name]Belle[/name] (This could still honor [name]Annabelle[/name], but I think it flows better.)
[name]Maia[/name] [name]Annemarie[/name] (This way you would kind of get both people you want to honor in there, maybe?)
[name]Maia[/name] [name]Juniper[/name]
[name]Maia[/name] [name]Verity[/name]
[name]Maia[/name] [name]Primrose[/name]
[name]Maia[/name] [name]Felicity[/name]
Some for [name]Serena[/name], too:
[name]Serena[/name] [name]Belle[/name]
[name]Serena[/name] [name]Lark[/name]
[name]Serena[/name] [name]Poppy[/name]
[name]Serena[/name] [name]Zoe[/name]
[name]Serena[/name] [name]Elise[/name]
[name]Serena[/name] [name]Chloe[/name]