My daughter was 25th for length at 15m but when we saw her paediatrician for her next check up at 24 months she had dropped to the 1st percentile for height.
They can change percentile a little bit as you move from length to height, in part because of how unreliable length measurements are - my daughter apparently shrunk 4 cm between 15 and 16 months! They just wrote that off the second one as being a dodgy reading as she wasn't cooperating with the measurements.
She was in 9-12 month clothes for over a year! She was checked a few extra times over the following 4 months incase she was still dropping but she went on to continue following the 1st percentile. She was 20 months before she ate enough to maintain her weight without also needing formula so may this contributed to her not growing upwards as quickly. She is now 5.5 and following the 2nd percentile nicely but since starting school 18 months ago she her weight gain has dropped significantly. She only gained 200g between July and January and she has now dropped two percentiles in 18 months.
She has multiple food allergies and severe silent reflux which is almost certainly contributing to this. She is also not a great eater. Her paediatrician did a test for coeliacs when she was little, I can't remember when, and around the age of 3 he did a stool test looking for malabsorption and any inflammatory markers. She has mildly but not significantly elevated inflammation markers and no signs of malabsorption.
We are at the dietician later this month and have another follow up with the paediatrician in 4 months to keep monitoring her weight.
I'm 5ft2, my dad is 5ft5 and his sister 4ft11 so we definitely have short genes in the family. That said it was reassuring to have that extra monitoring when it was discovered. It might be worth sending an email to the paediatrician asking for advice. They can sometimes only look at the last two measurements especially when you have switched to a new chart. For your own peace of mind it might be helpful to get your HV to recheck weight and height in 2-3 months to see what the trend is
We had this twice - the first time he compared It to the dodgy reading that hadn't been removed. I got her HV to check her height and weight 2m later and spoke to him about it at her follow up 2m after that.
This time he compared it just to the last measurement where it looked like she had just gone from just over to just under the 25th percentile. When he went back to the previous age chart you could see how she has actually gone from the 35th percentile to the 6th percentile. He opened with "good weight gain" to which I replied is it? His notes of the appointment list the drop and that it needs monitoring! It is perfectly ok to question them! I have copies of the chart on my phone now and a note page with her previous figures so I know where she was and where she is before I go into the appointment.
From an impact pov it's not held her back too much. We had to delay potty training by 3 months as I couldn't find any 12-18 month knickers so had to wait until she fitted into 18m ones to start potty training. It was then a faff that outfits in 18-24 m came with poppers vests still so she couldn't go to the toilet independently in them. She was in 18-24 month clothes until 4. I struggled to find a school uniform to fit her... Compounded by her being an August born - M and S and Sainsbury's do school uniforms in 2-3y. She's not the only child in her class that is this height and one of her best friends is older but only 0.4th percentile and they grow at about the same rate which is really nice.