They didn't own the mare at the time of breeding Ghost wind, the OP sold them the mare long after she was bred by their then stud colt. They turned a stud out loose with the mare before they gelded him because they could never get the mare in foal, she sold to friends, the mare ended up pregnant..
OP, you are not entitled to a stud fee, the foal or even training the foal. The foal and mare is theirs not yours. Plus, it kinda sounds a bit to me like maybe, just maybe, you "practically" gave them a 19+year old mare, and you are a tad bit jealous because they got the foal they wanted.