My missus is all of 4'11" and finding a bike was a nightmare.
Giant Boulder 12.5" just wasn't right and even with the shop offering to change stems, bars etc, it just was too much of a chew on.
Specialized Myka was a really good fit, but the only 13" we found got sold, and then the wait was until end of May for one.
She eventually got a Trek Skye S – it has a dropped cross bar,but it fitted her first time, no messing about, at 13" it's light enough for her to lug up and down the stairs into ours.
300 quid discounted from 325 – if you go up the spec I think it was 390ish for the Skye SL that had disc brakes.
I know it's not really that cool and off-roady, but it does what she wanted it to do.
Even had it around the Chopwell rollercoaster (parts of it) although I got knacked for taking her on it, it wasn't quite the nice ride around the woods she was expecting.