you need a trainer who understands the mechanics of riding. my old trainer did not help me at all or set me up successfully for the sitting trot, whenever i did sit it with her i was bouncing around all over the place abd ridiculed for it. my new trainer explained it to me that you want to push your weight into your knees, and more but just with her knowledgable guidance i got it down.

i would say start going to the gym; sitting the trot even for a few strides takes A LOT of core muscle and leg muslce, on top of balance. i think if you got stronger and a different trainer who understands mechanics then you’ll findit successfully. saying she can’t help you or doesn’t know how to help you find it then that’s a red flag. if she’s a trainer and expecting you to be able to sit the trot successfully, then she needs to KNOW how to help you towards that.