We are going to hold back and wait for our two 3 year old fillies this year. They both seem mature physically, and most of the time mentally. But I would rather wait than have them give up during foaling, or be a bad mom because I chose to let them breed before they were ready. I'd rather they be ready for the baby, than so-so about it. One of our mares was bred as a 2 year old, and foaled at 3. This was before we owned her. She was not really smart about her filly, although you would never have guessed it now. She's a great mom. Besides, my breeding stallion this year is a rookie (he's 3, and only bred one mare twice last spring). I'd rather give him a chance with the older mares who know what's going on first. I don't know what he's going to throw, so I'd rather wait for my two maidens than have them have potential problems from the stallion's foals. Now all that said, if King was a proven stallion, we might re-think not breeding at least one of these fillies (I want to show the other this year). But I would not choose to breed a 2 year old filly. It's just not worth it to me. There are too many risks involved.