I also believe your baby to be a silver black. Up in the air on her sire.
A silver bay is a black based horse (EE or Ee) with at least one bay gene (Aa) or two bay genes (AA) and one or two silver genes (nZ or ZZ). The silver gene only shows up on a black based horse. A "red" horse - also known as sorrel or chestnut - is red based (ee) and can carry a bay or silver gene (or two of each) but neither bay (agouti) nor silver show on a red based horse...
A bay gene (agouti) dilutes black everywhere but at the "points" of a horse (mane, tail, tips/edges of ears, around the eyes, muzzle, lower legs, sometimes the elbows & flanks). A silver gene dilutes or changes black - a black changes over the whole body and mane/tail change to flaxen and if a bay is carrying a silver gene - anywhere he has black will be a "silvery" color. To include a flaxen mane and tail and points.
Here is a great website talking about silver and the genetics of all colors (including some newer ones!) -
Animal Genetics
and if you Google Silver Equine you can get both their website and their FB page... Our stallion used to be pictured on the website - but when it changed hands, he somehow got removed...
A silver black or silver bay can also carry spotting genes - as many of ours do.
Here are our two silver bays. Both are tobiano pintos - one pretty minimally & the other w/ quite a lot of white. Both have the same sire.
Flower has not been color tested and neither was her dam, Star. However her dam was out of a black Hackney mare and sired by a bay Arabian stallion so Star only carried 1 bay gene to make that beautiful "red" bay coloring and Flower only inherited 1 bay gene. She would have inherited a black gene from her sire (color tested) as well as the Tobiano and Silver genes. So, genetically - Flower looks like this - E?AaZnTt and here's Flower's photo album from birth...
FLOWER Sorry, Flower's album in Picasa is only from about 8 months on... Here's the other album - the pics aren't in date order, not sure how to re-organize Photo Bucket. Every time I do, they get more "out of whack"...
Flower - PB
Dandy has also not been color tested, however, both his parents were. He has the same sire as Flower. He will be homozygous for black, homozygous for Tobiano, 1 bay gene from his dam and 1 silver gene from his sire & genetically looks like this - EEAaZnTT and because his pinto white covers most of where he'd be a bay (have black points) - he looks like a chestnut and white paint!! Here's his photo gallery -
DANDY
and then there is all those dapples and many, many shades!! No-one knows where those come from and why some silvers have them and others don't.