HI
I have had up until a month ago 4 very hormonal mares one who lost her foal at 10 days was the worst (now there all in foal thank god) one of the mares was put on a calmer equine america make one was put on magic naf make and the other 2 i changed there feed.
i would say the equine america calmer worked best but also the change in feed to a stud balancer helped them to cope.
I'm not sure putting her in foal would be for the best as unless you have somewhere for the foal to go you never know where they will end up.
Regumate works one of the mares is on it for the next 100 days or so but it is expensive and the other problem is that women shouldn't touch it with there skin if they plan to have kids.
hope this helps