A girl who lives across from me posted on my wall y an ambulance was at my house. I don't want her to know...?

My sister had a seizure (she's okay) earlier tonight and the girl posted on my facebook wall "ambulance"? I mean, I don't want to comment on it because then everybody will know, but yet if I delete it, then the girl knows something is wrong. I just think it's kind of nosey to ask. I don't know cuz I don't really talk to her that much. It would have been so much easier if she messaged me instead hahah. What to do? Thanks.