Believed uBPD mom's lies about my stepson... what was I thinking?

[NeedingPeace]

UBPD mom has been acting so normal for a while... well more normal than in the past.  She is really trying, our boundaries are being respected, and she just seems like an insecure frail old woman.  We had been letting her see my daughters (3yo and 11mo) for a while and all seemed to be well.  We then let her babysit the two girls and again all was well.  I have a stepson too who I love as my own. Every-time my mother was around him she seemed to be trying quite hard to get along with him, but she and her FOO have always had a "family vs. strangers" attitude, with everyone who is not blood a stranger and not to be trusted.

Anyway, last night DH's aunt is in hospital with only a few weeks to live at best.  Mom offers to watch all 3 kids so we can go.  After we have been there only a short time i get a frantic call on my cell - she is crying, saying my stepson is out of control, being so bad, that he grabbed and wrenched her arm, she is so sorry but we need to come home now.  We rush home, and give him hell for how he behaved, ground him - the works. 

Now a day later she says a couple of other things that don't add up. Now i am suspicious and start to remember that this is a woman who lied about having cancer, who falsely accused my dad of molesting my sister, etc etc... . it had been a number of years since she'd pulled any stunts like this but I am still furious with myself for having been taken in by her.  Turns out he had given her a bit of sass, she sent him downstairs and then when DD (3 yo) wanted to go play with her brother not granny all hell broke loose.  DD was prevented from going with her brother, leading to my mother barricading herself in the babies' bedroom with my 3 yo and the baby with her back against the door.  All the while DD is crying saying she wants to be with her brother. 

This sickens me... . how the f#%k could I have believed a woman who once accused me of beating her?  How could I have been so stupid as to let her be around my kids? I have apologised to my son for what happened but I still feel awful.

What do we do now? No contact, supervised visits only?

[Want2know]

What do we do now? No contact, supervised visits only?

As always, you have choices.

1) You can let it slide, knowing this is who she is, and hope that it doesn't happen again.

2) You can go No Contact and never speak to her again.

3) You can choose Controlled Contact, be cordial, but non-emotional, as if she is an acquaintance.

4) You can communicate your support of her good recent behavior, address the situation that occurred regarding your step-son, and set a boundary for future interactions with your children.

What do you think is the best thing to do for all involved, including your aging, mentally ill mother?

This is a good place to work this through.