To be honest, if you love Winter, then call bub Winter. Honestly. There are Autumns too. And Junes and Mays and Rivers and Willows and Forrests who are very happy people...

And then Johns, Daniels and Matthews who are teased at school.

I think Winter's a beautiful name, so I'd be reluctant to steer clear of that just in case she is teased, when she could get teased if she's an Isabella or Summer or Jane anyway. To be honest, I'd think it was cool if I was winter and my bestie was Summer. My bestie is my name spelled backwards and we think that's pretty darned cool.

Anyway. Off the top of my head:
Winona
Bronwyn
Guinivere
Winsome
Windy
Arwyn