Seeking advice or words of wisdom for handling serious family drama?

This issue could easily be thirty questions, so forgive me if I appear rambling. I just don’t know where else to go for help.

Many of you know at least a little about the issues between myself and my family. Three years ago I put my foot down after a lifetime of mental, emotional, and physical abuse, and after my mother assaulted me had a restraining order issued against her. It was supposed to last for one year. My mother extended her own personal interpretation of the order to include my siblings and my entire extended family, and an unlimited timeline. There has been no effort on her part to contact me, and I frankly have no interest in seeing her another moment of my life.

I regret deeply having missed the last three years of my little sister’s life – the assault happened on her 16th birthday. I’ve tried to stay in contact via phone and internet, but I feel she’s being encouraged to not keep in touch. I saw her at the mall two weeks ago, and let’s just say she didn’t share my enthusiasm at our reunion.

Today, I got a text message from my sister. First contact from her since we met at the mall.
“You should come see nanny”.

Okay. Random.

“Why?”

“She has cancer”

Oh. “What kind?”

“Lung cancer. Her live long wish is to see her first great grand child. And she is having to go through Kemo and radiation. She is at the ________ hospital ((40 miles away from my house)) for three days.”

I didn’t reply – I was driving when that last one came through. A couple of hours later, I get ”You gotta go see nanny”

This sounds nothing like my sister at all. I am 99.999% sure she is being fed what to say to me. It does sound like my mother. The demanding nature of the instructions – that apparently expected me to know from the start that my grandmother is in the hospital, even though I haven’t seen her since 2007.

I have never been close with my grandmother – at least not since I was very, very young – but I hold no grudge against her. And I would have no problem letting her meet my son. However, I know my mother well enough to know that she will be at that hospital every moment of the day she can get away with – to the point of driving the nurses insane.

So, if I go, I have to deal with psycho my mother. This could lead to anything from verbal harassment to physical harm. It will certainly not go smoothly – civil is not her style.

If I don’t go, I’m the heartless heathen that denied a dying 70 year old woman the chance to meet her great grandson. All I know of her situation is what was in the texts, so I don’t know how serious the situation is, but I can tell you how it will be perceived by the people who shunned me out of their religion because I dared call the police on my mother the night she choked me.

What do I do?