What is her pedigree like? My boyfriend has a little BS mare that's coming 5 this year and she was fairly small when we got her, but has since grown by leaps and bounds. Well, 3 inches since August... lol
When does she turn 2? I see some growth issues going on. She's very posty in her right hind pasturn, i'd keep an eye on that. Is she sore at all? This can come form growing too quickly and the tendons not having a chance to stretch and grow.