13 year old weight gain

[popmimiboo]

Should I be worried about DD1? She's 13 and has always been really slim and petite -bang on the 50th centile for height but around 25th for weight. She's sporty but has cut down on training hours due to homework (her choice) over the last year. She still does 4-6 hours of gym plus school PE every week.
Over the last year she's put on quite a lot of weight and really filled out. She's getting quite a tummy. She's always hungry and never full.

First -do you think it's normal to put on weight at her age (-she hadn't started periods yet) or do I need to cut down on portion sizes? (I do think her portions are too big but she's always hungry and will fill up on bread if she hasn't had enough.)

Secondly, healthy meal/ snack ideas, anyone

When you say she's put on quite a bit of weight, how much would you estimate?

Is she still growing?

Has she noticed the weight gain, and if so, does it bother her?

She isn't bothered at all. She is still growing and I haven't weighed her. Tbh, since typing this I think I'm probably over-reacting, it's just that she was so thin before. She's been out playing on the trampoline all afternoon so is certainly getting plenty exercise anyway.