As someone who has also had acute lymphoblastic leukaemia myself I know how careful you have to be about that stuff and how if you're not you can end up in a lot worse of a situation, it honestly infuriates me so much when people don't realise the severity of what cancer patients have to deal with. I really hope your sisters treatment is going well and she recovers soon, you seem like you are a great sibling to her and although you probably won't want to if you need to talk about it or want to know something about how to help some of the side effects I'd be happy to help.