Hormones and Erection

[beginner]

First I want to congratulate everybody for the very good forum we have.
Now the question: I have now a TG girlfriend who I first knew some years ago. Then she had erections just like me, and I loved that.
She was away 3/4 years and took some doses of female hormones by herself but stopped. Some months ago we met and started that relationship, but now she can't get erections anymore; but she can still cum.
I would like to know if the effects of the female hormones will disappear with the time, or if she needs to take now male hormones (with medical assistance) to be able to get erections again.
Bionca has already expressed some advices about that subject, but not to such a concrete question.
Thank you very much for your answers.
Beginner