Well, Silver can hide on a Palomino (IF the sire is a true palomino)
:
So Silver is a definite possibility.
She could simply be a light "shade" of Silver/Black (Silver Dapple) or sometimes called Chocolate Silver.
She could also be a Smokey Silver Black. ( A Black with the Silver AND creme gene)
She doesn't look like a Silver Bay at all, IMO.