I personally wouldnt intentionally breed at that age but at the same time if it were me I wouldnt be stressing too much. We kinda got into a disagreement (not a major one) about minimum breeding age. I say IMO and for me, 4-5 minimum. She says 6-7.
So I put it to the forum...should she be worried or just take extra good care of her if she is in foal? The horse is a well built little qh and the stallion is apparently only slightly larger than her.