Is Sandra rochefort a scam artist?

Yes, she is. It's been reported that she claims to be a psychic, and sends letters to people saying that she sees danger, but for $19.95 she'll protect them from the danger.

That she claims to be psychic really says it all.

(As a minor aside, in most states to see a person in danger and fail to act is a violation of various "Good Samaritan" laws, so if she was really psychic, she'd by law have to protect you for free!)