We bought the girls bikes about a month ago, M loves it but has no idea (due to her disability) however A loves it and she is pedaling, she needs a little help still as sometimes she gets stuck but she is picking it up quickly, she is still learning to pedal and steer, I am confidant that she will be able to ride along (with training wheels by Christmas). We got the bikes that are two wheeled with training wheels and the pole at the back so we can help push, the pole is easy removed along with the training wheels so it will be a normal two wheeler when they are ready, this may be a good idea for you also.

We have a balance bike but the girls haven't shown much interest.