This is very off. Smallidot is around as tall as amethyst, if you don’t count the hair, she definitely is shorter, and limb enhanced Peridot is rougly as tall as Pearl, not as Garnet. Rose differencse of size with Garnet is more than that, and she and Jasper are probably closer in size.

She was on her knee if I remember right. Plus Stevencrew stated multiple times that they don't use specific heights for the characters.