I agree with the others. She is not a good friend at all and has no business being so rude.
If you are the type to say something, you could remind her that you are not deaf and heard her the first time she "commented" on your weigh.
And, if 200-ish pounds was sooo terribly heavy for a horse, then I guess most men should never ever
ride a horse. At least not any manly ones.
I mean gosh, many "in shape" men weigh upwards of 200, then you add tack and all.... oh my, those poor poor normal sized horses they ride!
And just how in the heck did man ever conquer the west? I guess they all walked and lead their horse against the hostiles, or there were no such things as The Pony Express?
And horses have elvolved to only be able to carry little skinny girls who have no butts and use synthetic featherlight saddles... and... I think you get the picture.