Been there. My youngest son is extremely cautious and did not learn to ride without training wheels until he was at least 8. What did the trick for us was taking the bike on a beach vacation where it was nice and flat. We were in an area with paved paths right in front of our house, and it was easy for him to hop on the bike and try to ride it.
I don't know how practical that is for you. You probably can't pick up and go to the beach right now, but the key was flat and paved. If you can find a place that is convenient (a school track?) and let her go at her own pace, maybe that would help.
In our case, peer pressure was making him motivated get rid of the training wheels.
Grits
2010 Trek 5.2 Madone WSD, SI Diva Gel Flow
2002 Terry Classic, Terry Liberator