6 year old , smelly pits !?!

Cjay
So my niece is 6 years old, and her pits smell horrible! I had her for the weekend and made sure she scrubbed her armpits because I really didn't want to put deodorant on her because she is so young. I asked my sister if she has noticed the smell and she said yes , and asked her Dr and the Dr just said to make sure that she bathes her correctly, and mind you my sister is a clean freak and kinda got offended . I was thinking maybe early puberty? What do you ladies think? I told her she should take her to another pediatrician and get a second opinion as her and I both got aunt flow at age 8.