[She drops her gaze at that. It had been something she had been questioning herself for a long time]
Perhaps she questions it. She knows it's a love that fills her heart and yet knows it perhaps to be wrong somehow.
Other options:
no subject
[She drops her gaze at that. It had been something she had been questioning herself for a long time]
Perhaps she questions it. She knows it's a love that fills her heart and yet knows it perhaps to be wrong somehow.