more of my mom stuff + a question

yeah, another post about my mom.
We are going back to the state I am from (me, husband, kid) to see my aunt (she paid for the tickets). My husbands family lives about an hour away, he will go see them and I will too briefly. My mom lives an hour and a half away. We always go see her. I don't want to see her or tell her we will be in the area.
Yesterday I resumed counseling due to issues I am having with her and our past and the counselor (whom I adore) suggested we go back, see the people we want to see and not visit my mom.
But I am kind of freaking out about it - can I do this without being a horrible person?
The only reason I feel like we should see her is a sense of obligation. What happens if we do see her is I am stressed out, we will spend time every day before, during and after the trip (for about 3 weeks after) embroiled in " discussion" (her screaming and crying and pleading and then acting eerily normal) about how much time, with who, where, how often etc.
Our relationship is really quite horrible. I am (currently) terrified of her, can't be honest with her about much, don't want her messing with my kid's head, and so on. For the record she is actually crazy, not a normal person with in bad relationship.
So can I see the rest of the family and not her without being awful or having something awful happen? It seems so mean, but if I see her she is mean to me...arg.