When Sis was younger, she acted a lot like Duchess. Never acted bad even when around a stud. However, the filly that I am riding now, Prissy, is a royal nightmare when she is in heat. Touchy, grumpy, squealy, head flinging, tail swishing, witch. She will back up to anything taller than 3 feet whether it is alive or not, she has developed a strong attraction to the pipe panels of the roundpen and has thus bent one of them all to hell. }:( It just kinda depends on the mare and you are a very lucky girl indeed.