Student has gained a lot of weight recently. Should I say anything?

As the title says, one of my 10th grade students has put on a lot of weight over the course of this year. I’m not sure exactly how much and I’m useless at guessing but I’d say it’s probably 40lbs minimum. She wasn’t exactly skinny at the start of the year either, probably slightly overweight, but she is VERY big now.

I’m conflicted about what I should do about this. On the one hand, something could be happening in her personal life that needs to be brought to the attention of the school, but on the other, weight is a very sensitive topic and I don’t want to overstep any boundaries. I was very overweight as a child and it really impacted me negatively. I want to help her but I don’t know if it’s my place to do so. What do you guys think?

Edit: okay, point taken. I won’t make any comments on her weight