I had a Warmblood cross cob who was 14.2hh at 3, the following year, at 4, she was standing at 15.3hh. Admittedly she had had a very poor start though.
She's nice
But I dont think she'll make 16hh or over.
I've got a 2 yr 5 month dutch WB, she stood at 14.2hh the day I bought her which was the day she turned 2 years old.
She's now 15.2hh and is predicted to make 16.1hh - I think she will make the height.
They are probably the same age give or take a month - unless born at a strange tiime of the year - so she's a whole hand shorter than mine - so my logic tells me she will probably make about 15.1/15.2hh x
If you really like her it may be worth asking what height her dam and sire are, that usually gives a good indication.
But looking at her pics, she's in good condition which suggests she's not had hard start and has catching up to do, she's probably grown to her full potential to date.
The market is really good for buying young ones at the moment, so you will definitely get a horse just like her thats bigger for good money x