That all depends on her breed and her body type. If she typically looks thin and sports a large udder between her legs, then it's likely that she is a dairy cow. If she is more blockier, not quite as thin and sports a smaller udder, then she would be a beef cow.
That all depends on the breed. Are you asking about a dairy cow or a beef cow, and what breed of dairy or beef cow?
Yes.
Charolais is the best beef breed, and Holstein is the best dairy breed.
Dairy
Holstein-Freisians belong to the Dairy breed group of cattle. Beef Friesians, kin to the milking Holsteins, are in the beef breed group.
A chicken is neither a dairy nor a beef breed; it isn't even any kind of cow. A chicken is a bird that has feathers and lays eggs. Cows don't have nor do any of that.
The Dutch Belted is typically a dairy breed.
Nothing wrong with that. Dairy cows are slaughtered for beef as culls anyway, so it's no big deal if you slaughter a dairy cow and turn her into ground beef.
No. Gerts are a beef breed, not a dairy breed.
No. The biggest type of bovine is typically the beef cow. There are beef cows around that weight more than a big dairy cow, and that can be upwards of 2000 lbs or more.
Ayrshire breed is from Scotland.
The Jersey is the smallest dairy cow, but not thesmallest breed of cow. The Dexter is the smallest breed of bovine.