My sister in law has really been horrible to my husband and I and refuses after 3 years to apologize. ?

[Norhdberg]

If she's exhibited this sort of behavior for 8 years, why would you expect to get an apology now?

My guess is the facebook post is an acknowledgment that she knows shes been an a**, but she doesn't know how to make an apology or isn't ready to give one yet.

At any rate, it is too soon to tell if she's beginning to change her behavior. I'd say that you need to keep your distance from her until you can really see a change. Don't keep putting yourself in the same position with her if you keep getting burned.