What an unpleasant situation, and one that is difficult to resolve. Your step-daughter, or to use the old-fashioned term, daughter-in-law, is being extremely ill-mannered to you, quite deliberately so. She is neither disinterested, because she has a vested interest in you by law, as her father's wife, nor uninterested, as she is using her behaviour to sow discord between you and your husband.
I can appreciate that as a teenager she felt resentful towards you when you married her father because like many children in broken marriages she may have hoped her parents would reunite. But she is no longer a child, has a marriage and children of her own, yet is still pursuing a a childish vendetta against you.
The key lies with your husband: My husband tells me to just ignore her behaviour ; but it is very hard to ignore someone who is ignoring you. She is a guest in your home, accepts your hospitality but is deliberately rude to you, and your husband does nothing.
You say he is not confrontational and this may have led him to passively accept poor treatment from his first wife. That is no excuse for expecting you to tolerate it from his daughter.
As for advice: do not be driven from your own home and take an active role when she and her family arrive, however awkward; does her husband come too? Tell your husband your feelings and say how hurt and uncomfortable you are being made to feel, in your own home, and show him that you expect him to take some sort of action.
Unfortunately, I think the daughter will take umbrage and leave, which will achieve the desired effect of upsetting your marriage.