What could these be nicknames for?

I love the following girls' names, but they all sound quite nicknamey (except Gwen - Gwen is just a lot shorter than most of my other favourite names). So I was just wondering if anyone can think of any possible full names for them?

Dacey
Dalla
Della
Gilly (hard G like in gobble)
Gwen
Tru

I thought of Candace (Dacey), Delwen (Della), Galadriel (Gilly), Guinevere (Gwen), Gwenda (Gwen), and Gwendolyn (Gwen), but I'm not sure if the first few work. So yeah - what full names can you think of for the above nicknames, and do you think the six I thought of work?

Oh, and also, what do you think of them?

Dacey - Candace works well I like this.
Dalla - Dalila (dah-LEE-lah)
Della - Adele, Adela, Adelina, Daniela, Cordelia, Delilah, Delana
Gilly - Gillian (pronounced with the hard G), maybe Guylaine (gee-LEN)
Gwen - Gwyneth, Gwyneira
Tru - Gertrude, Trudy, Truda

Dacey - I think Candace works well
Dalla - Dahlia, Dalinda, Dalila
Della - Delilah, Adelina, Delana, Delany, Delaire, Delphina
Gilly - Gillian, Gilda
Gwen - Gwyneth, Gwendolyn
Tru - Trudy, Trula, Truda, Gertrude