Thanks! Yes, she's apparently been tested and was positive for hypothyroid. She's on a daily med and only get's about a cup of grain a day to mix it with. I'm not sure what the med is yet. Her pasture time is kept short so she doesn't founder so her primary food source is hay. I would think this must be contributing to her overweight-ness, not being out and exercising as much. I'm thinking about getting a pasture muzzle thing-though I'm not sure how i feel about them-i dont know much about them. I plan on getting a good vet over here and making sure she's on the right track health-wise.
I think i will take your advice, Classical R and do lunging/ground work with her for a few weeks. That way we can get to know each other too. It'll be good that it's almost fallish and the days wont be so hot on my poor fat pony!
Bringing home this pretty lady very soon! Can't wait!