Remember that people reading her posts are getting to see a different side of her. She is hurting herself and has no idea.
How you react will say more about you than what she wrote. If you are nice friendly and ignore her nasty comments, she is the one that "owns" them and they reflect only on her.
Should some one ask about why you did not "ask your husband", I would just look at them and say....."you really think I thought my Hubby not would notice a flock of chickens in the yard?"
Leave it at that, just allows her to own the "I am mean and nasty to family" FB title