Just leave it in her room or we're ever she is never busy and when she isn't busy go up to her and say "Mom can we talk about stables like you PROMISED"
But don't ask her too often or when she's in a bad mood/snappy
I think mom's just don't want to pay because
I had to beg my mother for a year before she let me join. Just show her you are responsible, that this whole riding thing isn't a phase, that you love it, that you've researched it so you know some facts, etc. hope I helped lo
That was my problem as well, I just asked about it, not like a pest but like, "so mom, how's the thinking about English riding going?" And ask when she is in a good mood so she doesn't get mad. And don't ask every day, but bring it up once and a while. :) good luck 😊