I was hoping some of you could give me some insight on if I should be worried about breeding her in the future.

I have a pony mare that I have planned on eventually breeding but I am a little worried about if she could handle having a baby... She has little to no pain tolerance; at all! In general she is sensitive, but even the vet was joking that she had never seen a mare that was such a wimp after an emergency call for what she acted like was a broken leg (hopping on 3 legs and moaning) that turned out to be a sprain and 100% sound after 1 day of muscle relaxers.

Has anyone ever bred a mare like this?