No height growth?

So my husband had DD at her 15 month appt this morning and again she was 30.25in and 23lbs she’s been at 30in since her 9mo appt and I guess the doctor said if she doesn’t go through a growth spurt by her 18month appointment they would need to run some tests. Has anyone else gone through this or are we the only ones. She’s eating relatively well(aside from when she’s cutting teeth) she says hi, bye, hot, sit(dit), mama and dads occasionally but she understands so much more. She runs and climbs all over everything.

At her 12mo they were guessing that they hadn’t measured her right because she never sits still. Picture because she’s my little stink.