I have a 16 year old mare that I bought in October. I went and rode her where owner had her stabled before I decided to buy here, and she was perfectly quiet and did everything I asked. I would have considered her bomb proof. I rode her around other horses she knew and some she didn't. I worked with her alone and she was great. There was one horse she had been with for 6 years, and I was told she was particularly attached to that horse. However, when I separated them, she was fine as long as she saw other horses around.
When I got her home, she was introduced to another mare I've had for years. They get along just like all mares - if too close they fight, but otherwise fine. The new mare is still very quiet and gentle when she can see the other mare. I even caught my 4 & 5 year old granddaughters in the back lot with both horses loving on them - which the girls were told never to do again without grandma or grandpa with them.
My problem is, when I separate the two mares to work with them individually, they get really crazy and almost un-manageable. My older mare will calm down and listen to me after a while. The newer mare will eventually calm down if she's in an area she's familiar. If she's not familiar with the area (front of the house instead of out in back of the barn), she's hard for me to handle - stamps her feet, rears, throws her head and snorts. She's a little over 15 hands and I'm not, and she's strong.
Since she calms in familiar territory, it makes me think I can break her of this bad habit. However, I'm not sure the best way to "train" her so she's calm and can be ridden alone. I'm trying to separate the two a little at a time every chance I get - sometimes several days in a row, unfortunately other times I can't work with them but on weekends due to my job.
I don't want to have to always ride the two horses together as my husband and I have very different schedules. We need to be able to work with both of them separately. My husband's very willing to help out, but has never owned hoses before. I'd appreciate any help I can get from experienced horse owners & lovers out there.