Maybe try Cole Deelah at sagemama.net
Jessica Gonzales- Village Birthworks
Katherine Stanglin (she does hypnobabies but may know hypnobirthing)-Hypnobabies of Greater Houston
Tina Verstrate-Mama Bear Care
Amanda Moore (not certain she goes to TX Women's but she's worth contacting)- Holistic Expectations
Patti Heimlich-Houston Pregnancy Massage and Doula Care (she was my doula trainer and I am pretty sure she has a good rapport w/ that hospital)
The Motherhood Center doulas
These are some of the doulas in our area that I really admire. This list is by no means everyone in the area. A simple google search will take you to their websites and contact information. These ladies really know their stuff! Good luck with Hypnobirthing. I didn't take the course but the book helped me so much.