Allison is fine, IMO, although I do actually (for some reason) like this name spelled differently. Usually I hate kre8yvve spellings, but for
Allison I like
Alison, Allysen, Allasyn, etc. That's just me though.
There are a little many Allies, but I don't mind it. It's cool, girlish, cute, and can also be mature.
Callie is also cute. It's very fresh and pretty. I also like the spellings
Kali, Cali, Kally, &
Kallie.
Overall, I think
Callie stands alone better than
Allie, which I would prefer as a NN for
Allison.