My DD has a genetic deletion so it was much easier for us to get things picked up on as she was already 'in the system', and it was recognized early on that her lack of growth was likely as a result of her condition.
We were referred to an endocrinologist who did tests. They found that she has an under active thyroid ( Hypothyroidism) and she now takes levothyroxine supplements.
The tests found that she does not have a growth hormone deficiency. However, it was clear that she was struggling to grow and was very low down on the percentiles. She was noticeably much smaller than her peers.
They recommended that she takes growth hormone therapy anyway, as there are no side effects (or rather, side effects are very rare), and would give her the much needed boost.
She has been on it for around 2 years so far and last year she grew 10 cms!
It involves a simple injection every night. This is the medicine and syringe that we use: www.zomacton.com/why-choose-zomacton/
So my advice would be to push for a test for both thyroid and growth hormone.
Does your daughter have any stomach problems? Worth also looking into coeliac disease, which in children can cause what's called 'failure to thrive'. www.coeliac.org.uk/coeliac-disease/coeliac-disease-in-children/
My DD was tested but found not to have coeliac disease - or at least, not yet! My mother has only recent been diagnosed in her late 60s, so it's something my DD might develop at a later stage (it runs in families).
If your DD has any of those symptoms, worth looking into as well.