Arina is an unusual name. It is a variant of Irina which is the Russian equivalent of the feminine name Irene. Irene is Greek in origin and is said to mean 'Peace'. In Greek mythology it was the name of the Greek goddess of peace.
Site says Saanvi means Goddess Lakshmi* but i want to double check before going for this name. I think in Urdu Saanvi means 'secondary' not sure what it means in hindi or sanskrit. Some site says Anvi in sanskrit means Some Devi, but didnt find any ref. in sanskrit dictionary. (