Monster In Law

I am not married, but I am in a committed relationship, and his mother is a bitch  hell on wheels.  I am not an expert on how to deal.  I have dealt poorly in the past, and when I know she is coming over for a surprise visit, I immediately become MASSIVELY depressed and pray it doesn't last long.
She is  so nasty and so rude *NeNe voice* and she is religious to boot.  Most of all, she has done some specific things to rub me the wrong way.  The offenses are as follows:
1. Baby Shower Invites
This succubus lady was in charge of two things for my shower: securing a venue and sending invitations.  She not only did not get a venue in time, she sent the invitations out so late, my family was not represented at all.
2.  Babysitting Fail
She was supposed to watch our daughter for one night.  Not only did she drive an hour to bring the baby back, the asshole imbecile child of God honked the horn in the parking lot of the apartment complex at 3:00 AM.  Even her husband mentioned the baby had been sleep majority of the drive.  The sad thing is she is such a jealous, angry and miserable person, she is upset every time the baby spends time around any other grandparents.  She is even jealous of my daughter's gifts and attention.

As you can see, not only do I dislike her with good reason, I am not looking to find common ground.  I really don't care if I get along with crazy people.  I just thank God we are moving and will be in a lot less contact with her.  I am looking to make myself as scarce as possible when she does visit.

*update: 5/27/2014 It has been brought to my attention this person may be in my life to teach me unconditional love.  You only strengthen your ability to love difficult people by loving them.  That's my balance for the day.*

Sorry for the lack of happy happy joy joy.
This is Realest Mother Dearest signing off.