I definitely think
Camilla would work. To be honest,
Millie seems more of an intuitive nn for that name than
Cammie. I don't like
Mildred just because it makes me think of mildew. :( My dd is
Emilia and sometimes we call her
Millie. :)
My PNL:
http://www.behindthename.com/pnl/125425 (rate if you'd like)