My computer isn't in the mood to let me click on the pictures and see them larger, but from what I can see, looks good.
My oldest started 5-stepping just over a year ago, I was so not ready and still stress about it. She was almost 11, I'd expected her to need a booster until closer to 12. I'm coming around to it. My just turned 9 year old is way too close to 5 stepping for my taste, but I'm just going to hope she stays at almost until she reaches and age when I will feel more comfortable...only have a couple inches and it just depends on where she grows them. I so feel your worry.
She does appear to have good fit, just wait until someone who can see it bigger agrees to be certain. I don't want to leave you astray due to the pic being too small for me to be certain.
Hugs to you, they grow up too fast!