Forcing Young Sibling Not To Fast
I think, ultimately she has to decide herself. Forcing may lead her to fast without even sehri. May be @Irfan76 sb can give his scholarly opinion on this matter.
but her decision can harm her badly after every 7-8 days….she has symptoms of tapeworm
You cannot force her, she is young, but can influence her, persuade her, take doctor’s advice, etc.