Alaia is pronounced ah-LIE-ah. There was a child with that name in my kindergarten group when I did an internship in Basque Country and I've loved it ever since. The only nickname I can think of that I like is
Laia, but I don't think it needs one at all. I think it goes well with
Xanthe and
Adelaide but doesn't fit in with Sonnet and
Summer at all. The combo isn't my thing at all, so I can't say.