You need to go back to walk and get her to accept your legs. Do lots of halts, changes of rein, figures of 8, circles and serpentines.
Some horses esp TB are ultra sensitive, so at first its best to be as relaxed and soggy as you can be and get them used to having your legs just draped but in contact with their sides, let your seat and thighs move with their stride so you can feel when each back leg steps under and have a nice soft elastic contact.
When she is happy and relaxed begin to sneak in the odd gentle lower leg (calf) aid, the first response is normally for them to rush forward, stay relaxed, allow her forward for a couple of strides (don't pull the reins as they normally shoot forward with thier heads in the air and they'll just balance and lean on your hands), use your hands individually close/release each rein and with each rein aid block forward motion with your seat until she is listening and then start again from scratch. It can take a long time, its lots of repetition, practise and mountains of patience. It's best done in a school, and with an instructor, you can't beat an experienced pair of eyes on the ground.