She does look a slightly odd shape on the one pic especially but hard to say from photos.
How old is she? If she's still a baby she might get a bit heavy for you when she matures
You would have to see her and ride her to judge really how she moves and if she seems like she she has the sort of attitude & 'go' in her to jump and the paces for dressage if that's what you want to do.
Size doesn't always go against them. There are a lot of gypsy cobs doing dressage really well and I've put a link here to old footage of a horse called Ryans Son jumping in the Olympics who was only 15.3 and said to be a Clyde x TB