My ds(7) is a poor grower and diagnosed with short stature (this is actually a side effect from a genetic disorder that has since been diagnosed) so I've been where you are trying to decide whether to see gp, we were a bit younger than your dd age when we did.
Go and see gp. They will measure and track her. Likely they will then ask you to return in a few months for remeasure to see if there has been any change. Poss also look at doing bloods (insulin like growth factor is worth asking to test for as this is can be a flag but isn't routinely tested so might need to wait for paed referral but can always ask)
After this, they should refer you to a paediatrician for monitoring. Make sure you ask for the hand X-ray to establish growth age (we have a 2 years growth delay so they think/hope he will just keep going for 2 more years compared to everyone else)
We were also then sent for growth hormone testing which were negative so we were back to sq one but the endocrine paediatrician was fantastic at going through all the possibles and ruling everything out (this was how we eventually got to caused by nf1 as process of deduction).
The outcome for us just knowing but being unable to do anything about it was still worth it because it ruled out worries and concerns and also meant we put into place coping strategies for being smaller (reaching things, strength, activities etc).
(For context, ds is off the chart at the bottom and is 105cm tall age 7 end of y2- I think he was about 99 at the end of reception)