First, you are NOT terrible for wanting to keep your T to yourself. Seeing that your needs are met does not make you a bad person or a bad mother, and I agree with those who have said that your daughter CAN seek out and find her own therapist. In fact, I think that when someone is really ready to heal, they will do whatever it takes to find a T that can help them, and that this is part of beginning to heal in itself.
At the same time, I would also suggest that it does not have to be you OR your daughter with this therapist. I did read your other thread, and I think that if you have decided that you are just not comfortable with both of you seeing your T, then this is perfectly ok for you to make this decision, BUT, for what it's worth, I can tell you that my sister and I have been seeing the same therapist for many years, and before my brother died, he saw my T too. Truly, it has been a positive thing for us. I feel like it offers my T a greater perspective regarding our circumstances and strengthens his perceptions and understanding of my life.
On the other hand, when my mom was looking for a T, I did NOT want her to see mine, SO, I asked mine for referrals for her. Since, I trust him, I felt really good about offering her the names of T's that he recommended. Is this an option??
Clearly, there is no right or wrong answer here, and you are not doing anything bad or wrong by choosing what works best for you and meets your needs.