Does she have feathered feet/shanks? Two out of the three five toe birds I know (Faverolles, Dorking, and Silkie) have feathered feet. Doesn't mean it passed on, but I noticed some people say Silkie/Cochin cross, which would have feathered feet/shanks.
A Silkie cross would probably be the most common, considering the popularity of the Silkie. If it is a silkie cross it should have darker skin, and very soft feathers. It may also possibly have feathered feet, a beard, crest, and a walnut comb. Most of my Silkie crosses have remained rather small, maybe not even over 4lb.
Faverolle, and Dorking are your larger five toed fowl. Faverolles also have the feathered feet, pea comb, and a beard. Dorkings do not. However, Dorkings I would think are the least common.