Take the pedals off, drop the seat and let her scoot around like she did on the balance bike. When she gets the hang of it, put the pedals back on. Don't obsess over optimum seat height for pedalling, being able to reach the ground easily is more important than biomechanical efficiency at this stage. Gradually move it up as confidence builds.
MikeD is the man you should listen to. It's the best way to get her comfortable with the weight of the bigger bike, but in the comfort zone of a balance bike which she'll remember.
All my three are riding. All started on balance bikes and never touched a stabiliser. Two girls were on 14" bike by 2 1/2-3. My son was on balance bike before 2. He's now a demon. Not ready for pedals yet but not too long.
Balance bikes are the fast track bike school. Plus they seem to have the ability to make kids LOVE cycling long before spills and fears set in.
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