I do like Rose as a middle name, and love Grace! Sunday is pretty, as long as people don't shorten it, since it is her first name. I guess I like both of them overall, just not together! Maybe b/c I am southern, a nickname Sunny just does not sound feminine.
My mother named me Tamara for a reason, and would become highly agitated when people would refer to me as "Tammy". No offense to the name, my mother always said, but I named you Tamara for a reason. However, I do call my daughter Bree, short for Aubree, but only around the family!
By the way, I think Mai is a gorgeous name, and would consider that if I had another little girl. It is different, sounds very feminine and sweet, and can follow her as a wonderful adult name as well!