Agree wholeheartedly with converting her bike into a balance bike. We teach one or two kids to ride most weeks and there have been, over the years, youngsters with autism and dyspraxia. One of the latter was 14 and so severely dyspraxic he had difficulty walking alongside the bike without falling over. He learned after 4 weeks (2 hour sessions).
The saddle needs to be low enough that she can get both feet flat on the ground. This helps to reduce the fear of falling. Get her to "walk" the bike along while keeping her weight on the saddle - there's sometime a tendency to get off it,, which rather defeats the object. Once she has the confidence to lift her feet off the ground for a few feet you can try what we do - get her to count how long she can go without putting them back on the ground. This often distracts them from panicking unnecessarily and provides a challenge at the same time.
If you need to give her a bit of a push at sometime, don't push the bike, since you may not be pushing her in quite the direction she's steering. Place your hand lightly on her back between her shoulder blades. This helps her while still allowing her to maintain control. I often use just my fingertips.
We also use a slight slope onto the all-weather soccer pitch to help them get a bit faster once their confidence is rising. Once she starts pedaling, the following tips help: (1) make sure she looks well forward and not at the front wheel and (2) get her in the habit of always starting with the "pedal up/pedal ready" position, i.e. with it level with the down tube rather than pushing herself along with her foot on the ground to get up to speed.
Once she starts riding, play the counting game again. (Training wheels are the instrument of the devil and should be thrown into everlasting fire).
Good luck because she will learn to ride.