I think Millie could work as a nickname for Matilda, too!
Josephine Joie, Sephie, Joss,
Miranda- Minnie, Mindy,Miri
Seraphina- Seri, Sephie, Sina, Sia
Clementine- Lemmy,Clea,Cline, Mint,Tine,
Domenica- Minca,Demi, Deni
These may not make sense to anyone but me. I have some good friends with less common nicknames and I know their lovely/clever names have influenced my thinking.
Aurora nn Arrow
Penelope nn Peony
Lorelei nn Rilla
Tons more I will add when I am on the laptop tomorrow!