Don't tell me how to handle my pregnancy

So I've been experiencing severe nausea and vomiting, I've been to the ER 3 times in 3 weeks for fluids and meds, my doctor finally prescribed me Zofran and it's been a lifesaver! I know with any medication there's a risk for side effects to the babies, but I don't need people telling me how I should and shouldn't be handling my pregnancy, my sister just had her first in October and she's become such an overbearing person! I didn't tell her what she should/shouldn't do in her pregnancy or with her baby once she was born, she knows I've been having nausea but she doesn't know how bad so when I tell her I finally got some meds and tell her it's Zofran, she says, "Heather, you sure about that?" If my doctor didn't think it would be safe, I doubt she would have prescribed it! She doesn't know I'm having twins, I'm planning to surprise everyone at Christmas, end rant, sorry just frustrated.