Not YOU @Goldencoast2, the OP!
There is a parallel thread running where OP wasn't going to weigh DD for a pony camp & was just going to use DD weight from 6 months ago and hope stable wouldn't check it, so DDD could continue to ride her favourite pony 😬🤦♀️
But I am getting an inkling that the "obvious" gain might be more in the 3-5lb range than the 15-25. Can't put my finger on why, just gut feeling.
If it is more like 15-25. it's still no big deal -it's what happens to human bodies when we have an excess of energy - we store it as fat. Having a short discussion about how a parent can help a child balance out their energy in & out as they move from growth & puberty to an adult body; from school PE to optional college sport; from family meals to making their own food & food choices shouldn't be a big deal if there is no huge body image/weight control/regular commentary on others' physique from OP.
And having the conversation gently after 6 months makes a lot more sense than leaving them to steadily put on 15-25 lbs every 6 months for another year, then leave home to continue on the same path. Providing some familial support to even out the energy balance with some more regular movement together would be a caring, sensible & encouraging thing to do as a group.
But helping DD without expressly suggesting she needs help (like by trying to find a movement based activity they could enjoy together, or involving DD in selecting favourite healthy meals & cooking together) really hasn't landed with OP. Seemingly because she's not actually overweight herself so she can't grasp that there might be any value whatsoever in offering to do some activity WITH her DD for moral support (and potentially a closer bond?).
I wonder whether she's still waiting for a script that's worked for another poster along the lines of 'We told Cressida it simply wasn't acceptable to tip the scales above 130 lbs, so we shipped her off to Champneys for 4 weeks last summer hols & now she's looking marvellous, that's all you need to do for your own DD dahling, surely?'
[Whether 'Cressida' would be teeing up to go no contact, or nurturing an eating disorder, who knows? But god forbid that with a DD of 17 anyone might need to do anymore actual parenting or engage in the art of an open 2 way conversation, or do some exercise with them for encouragement, eh 🤷🏼♀️]