I think that making one girl study more has less of an effect on her self esteem than taking a carton of ice cream out after dinner, scooping a bowl for you thin daughter, and not giving a bowl to the fat daughter because she is fat. Doing so would be a reminder of her that she is overweight, and I am quite sure she gets enough reminders during the course of the day as an American teenager.
Sure, the D student needs to study more. But the fat one can't be the only one to not have ice cream... the whole family needs to not have it. Otherwise you are singling her out.
I think the difference is that, IMO, making one study more = less of an impact on mental health than not giving her dessert because she's fat [while the rest of the family eats it.] "Time for you to leave the table so we can eat dessert." You'd really do that?
maybe she's born with it, maybe it's chlorine
If you're injured and need some sympathy, PM me and I'm very happy to write back.
disclaimer: PhD not MD