You sadly did not have a exclusive to that treatment, nor attitude.
Horses are a luxury, a very expensive luxury.
That said, those who have horses are then able often times to afford the nicer things...the chic, fad fashion of the moment.
Kids are kids, that often are cruel and vicious in comments, attitude and the cliques made to exclude others.
Its OK for your daughter to see it, even have to deal with it some, but not to be overwhelmed by it...
It is kids being kids as we all were at some point in our life. We all teased and gave another a hard time, name-calling or not picking someone for a team sport in gym class...we all did it.
Your daughter even at her young age needs to learn how to pull up her big girl panties and march on ignoring the tormentors or she will never learn how to ignore and find her own self-worth, self-reliance and how to stand on her own feet as a independent thinker and doer.
FYI...teachers don't condone kids being this way to each other, but don't jump in to defend either...they must learn how to handle it in their own way, right or wrong is what I often see. Now, I too am not from a rich family, both my parents worked hard for every dollar that came into the house, I babysat as a teen to afford lessons and then a horse was bought and kept on a friends farm living in a section of old abandoned chicken coop is not "rich"..that was my first horse and I did all of the care and feeding by myself. For my parents, it was less costly than having me start to run with the dangerous crowd if I was occupied elsewhere, and once a horse came, my time and energies were devoted to him....
So, you need to find a barn where kids are not allowed to treat others that way, but honestly,no matter where you go there are
going to be kids who own their own and have a larger spending account to play with.. Its life.
The diversity in life is what makes some stronger individuals and some weaker and always whining about how unfair everything is to them.
Kids are not dumb and know they can't act or treat others certain ways in the presence of some and can get away with bad easily when different adults are around or in charge.
What you can do is encourage your daughter to ride her best, do her best and ignore the other kids best she can...she will find other kids like herself and they gravitate to their own group.
Tell her it is difficult and sometimes it does hurt, but this is part of how adults treat each other too.
It isn't nice nor pleasant, but to do her best and walk-away from the unpleasantness is best.
Your daughter may only have lessons, so she be the very best in her lesson listening, working hard and learning new things...
She earns what she has, not it be given to her because the parents can afford, but when it comes down to it...in this case, she will become the better equestrian by riding the different lesson horses and ponies not just one horse all the time.
Oh yes, you can tell when you go to a upper level show and see who had their own and who had to ride whatever, a ride-off is called and those who rode everything fly through where the one who had everything handed to them fall apart and can't...then whine how unfair... Been there done that, seen it and lived it..
And often the whine of they don't like me, they picked on me, they made fun of me is heard from the child who often is ring-leading at the home-barn now is not such hot stuff...
You can not
fight her battles, but you can
prepare her to have self-respect for herself, how to respect but not like others, and how to treat those she not especially like with respect but that is far different than liking them.
That makes her different in she earned, she was not "entitled" or part of the ribbon/trophy for participating cause it isn't that way in the real world which even at her young age is fast-creeping up on her...
So many of our young people today have no clue...
Prepare your daughter to be a confident woman, not allow others to treat her certain ways, to stand for what she was brought up to believe in...to be a independent thinker and doer.
She will attract more friends than ever when the other kids recognize she is fair, she is nice and she doesn't bully...and that attracting will not take long to happen.
You as mom, be her champion, encourage her, wipe her tears when the kids are mean and teach her she is better than them in so many ways...give her the encouragement to meet the stare and glare head-on cause when stared down the bully often runs in fear... and teach her when it is appropriate to go to someone for help and you go with her again as her champion!