Yep follow your instincts that's what they're there for
Also unless she was weighed completely naked I wouldn't follow those weights to much, to many variants like was the first nappy wee'd in more etc.

GPs don't always know best, some of them are hopeless.

My DD hasn't gained weight since 8mths and is now 10mths but she is only a little thing, but still looks healthy and happy she is also no longer on the graph doesnt even make any of the percentiles lol