Nothing that proper care and training probably can’t fix. She is standing slightly toed out on the inside hind, and it’s hip-down, indicating a soreness issue. With most OTTBs, it’s an S-I issue. As long as it was due to strain and not an injury, it can be rehabbed within a year. 6 months rest, then afterwards an exercise program to encourage the horse to move in a long, low frame that allows her to stretch while engaging her back. It starts with walking, then moves to walking over poles, still allowing the horse to put his head down. Then it goes to hill work, then builds up to trotting, still with the long and low profile. Eventually, it’s an hour of exercise, with 30 to 35 minutes of trotting, and five minutes of canter. Are you willing to giver her the time and dedication?
She is slightly downhill, so you will have to work longer to get her uphill than a naturally-balanced horse. She will be fine through the lower levels, though.
Can’t tell about her hooves without seeing a pic of the bottoms, especially the hinds. Usually, OTTBs have a contracted heel, thinner soles, and a skinny frog, all of which can be corrected over time if you have a knowledgeable farrier.
I think the white patch at her girth is troublesome. That, to me, indicates trauma to the girth line, because most TBs are not naturally paints.
The shoulder is not sloped enough for high-quality gaits, so she probably will not be able to reach the lengthening required in advanced dressage.
It will take dedication, but she would be fine as a lower level dressage prospect.