My friend's mare has typical marish attitude and we really like that about her.
But lately when we're out, if she thinks she's getting left behind she'll give a buck or two in annoyance if she isn't allowed to gallop to catch up. She also will refuse and offer to buck if she is expected to walk out before the other horses after mounting.
She is not normally a difficult horse to manage and she gives up pretty quickly if you let her know you won't take any nonsense from her. I've ridden her quite a bit without any problems, but she has gotten really bonded to my gelding who is also her pasture mate.
My friend's a good rider but easily scared because of a really bad fall several years ago.
Any suggestions how to nip this in the bud?