Dropping a percentile

I haven’t weighed my LG since her 10 month check up and I weighed her today and she hasn’t really put a lot of weight on in 5 months. She was always 91st percentile and is now on the 75th. Was 10.06kg at 10 months and 10.50kg today at 15months. Is this normal as she is moving around a lot or should I contact the HV?