Theres a possibility my two year old filly is stunted, according to a former employee of the breeder. I was given some vague details about her dam rejecting her, and an accident as a foal.

She's currently 14.0-14.1. Officially turns 2 in May. So not necessarily small for her age, but she's definitely behind the other 2 year olds from the same breeder. Both parents over 15hh. 

2 Questions

Is there anything specifically I can look for that will indicate she's definitely going to be stunted?

Also, if she WERE to end up stunted, what are her odds as a broodmare? It's not genetic, so would it be passed on? Would she carry and deliver a healthy foal? Considering options, since she has really nice papers. 

I've had one foal be pretty punky until he was nearer the 3yo age - as in still 13h ish until then. He turned out to be a nice 15h horse. Two orphans, one turned out to be nearly 16h with both parents under 15h, one turned out about 15.2h with mare 15.2h and sire 15h. And one filly who was very seriously ill as a foal who didn't start growing until her yearling year, then sprouted and is now 15.3. Mare rejection or illness/injury isn't going to stop the horse from attaining it's full growth. If your 2yo is already 14h then you have a long time to continue growing. Correct feeding is most important. Some get big quick, some grow over time, some early, some later. 

I would give it time. I was in a similar situation last year. My filly was 14.1HH and her mom is 15 HH and her sire was 15.2 HH. I think it is easy to compare our young horses to these massive ones we see on social media running time onlies as 2 year olfd but not all horses hit their growth spurt that fast. My filly has finally started growing as a 3 year old and filling out. As long as they have a really good diet with quality feed, you just have to give them time to mature.

I would definitely give it some time. I like the Purina Growth and development until they are at least middle of 3 yr old year. And of course great forage with some alfalfa.