>>42677608 (OP)
AB would make a better mother if you want a large family. She's younger and can start pumping out foals sooner.
AJ would only just want 2-3 to raise. And she's very goal oriented and head of the family business. She can't spare all of her time for family stuff.
AB would hate raising the first couple of foals, but then become addicted to it. Always needing her belly full with a new one on the way. I'm just picturing one of those black and white photos with a woman and her 30+ kids. That's AB.