Monster-In-Law

Jessica
So my monster(mother)-in-law asked me to lunch this past weekend. I'm pretty sure she's trying to get in my good graces before baby arrives... but she doesn't have a good track record at all.... She yelled at me for 3 hours, that I wasn't what she expected as a daughter-in-law, when my husband and I got engaged and many other times include this past Christmas Day.. We were the only couple to show up her other sons didn't and I was the one who thought she might need to see a son on Xmas... She was angry at her other sons for not being there and took it out in us. It didn't even dawn in her own son to ask about coming over for Xmas. Apparently she thinks she was entitled to more time w/ her sons reguardless if they want it or not. If she's not getting her way she yells and picks a fight w/ my husband and I because we're usually the only ones in town. She has 2 other sons.  I am so tired of her shenanigans I don't really want to entain the thought of lunch at all. I understand this is her first grandchild but how do I let her know I have my guard up and don't really want her giving me unwanted stress. I scheduled a lunch w/ her to appease my husband but I have a feeling it's only to push what her agenda of what her role as grandma is on me. I am going to be a stay at home mom so her baby sitting isn't really an option I need or want to entertain either. Any thoughts???