If she's a female bovine that has had at least two calves, then she should be called a cow. If this "cow" is anything BUT the definition above, "she" would be a heifer (a female bovine that has had...
A call people use to get the cows to come to them for feeding time, to be put through the handling facilites, or be loaded onto a trailer and sent to some other place.
The English language has no term for a relationship between you and your husband's sister's husband. Most people would not consider her to be related to you. You could call her your sister-in-law's...