Well
Adele actually isn't too frilly for my taste. I only find
Adela to be frilly. I don't like
Adele because it makes me think of the singer.
I guess I don't really think of
Della as a nickname. I didn't really know it was one till I looked it up. It's very hard to decide which idea is better for me. I'm not really a fan of any of the sound of any of the names
Della is short for, I like to think of
Della as a form of
Adela though.