For a rider who is 4'11" and staying there I would recomend a small frame with small wheels. In the racing world this would be the 650c size rather than normal 700c. Smaller wheels are easier to handle and can help prevent toe-wheel overlap.
As you are growing rapidly you may be Ok with a smaller 700c bike.
You could also look at roadifying a lighter-weight MTB. Fit some slick tyres, bar ends and perhaps some higher gears and you will be fine for most non-competative road riding.