It's hard to say, because there are an infinite number of possibilities. It really depends on what your daughter's last name will be, because it has to all flow together. Everly Autumn is cute. I don't care for the name Sierra or Sienna. Too many syllables for my taste, but I'm a bit OCD about the subject anyway. What are your tastes? Are you looking for something different, simple, rare, old-fashioned, hippie, delicate??? Here are a few varied suggestions without knowing your tastes, your last name, or how many syllables you prefer:
Everly Rue
Everly Hope
Everly Jane
Everly Pearl
Everly Adele
Everly Nova (means 'chases butterflies' in Hopi Indian)
Everly Violet (too cute)
Everly Willow (this one is adorable. My daughter's name is Willow)
Everly Mariah
Everly Blue
Everly Belle
Everly Rose
Good luck!