I rescued a coming 3 yr old Appaloosa filly back in 2001. She was just a few months before her 3rd birthday. She was 14.1h and 700 lbs. She grew and filled out until she was 6 yrs old. She ended up 15.2h and 1,100 lbs. I found out her sire was 16h and dam was 15.1h, so it doesn't appear she was stunted from her 1 yr of poor care. She's my avatar
Drafts and draft crosses can and will continue to grow and fill out until they are 7 yrs old. As long her malnutrition didn't cause any bone density problems, she should be fine.