How can I help my sister-in-law realize that her dying Mom is holding her as an emotional hostage?

Perhaps brother talking to in laws and asking for their help for his family is a good idea since they are all aware of what is going on. That would free amy up to take care of her mom. Amy's mom is dying, afraid and in a new environment and amy is her "go to" daughter.

sorry, I didn't edit very well "no one" not "know one"

Yes, maybe one of his in laws can reach your SIL!

I realize you're concerned for your brother's family but if this is a recent development in your SIL's mom's life, then I think you can safely attribute it to her being recently given, basically, a short life sentence. You say she recently moved into an Assisted Living Facility so she probably has a Social Worker or Care person assigned overseeing the situation. However, you also say you live a state away and it's possible you might not have the full picture of what's going on. Yes, your brother probably IS stressed out AND tired BUT if the shoe were on the other foot, do you really think his wife would be complaining that your parent was was asking for all of HIS attention and putting all of THEIR demands on him? Or would she quietly go about the task of taking care of things so he could spend as much time as possible with your parents? My 2¢: he's an adult, if he's not asking for help and you hear stress, then probably that's because he IS stressed. My suggestion: offer an ear so he can vent, if the kids will be on vacation maybe offer them a chance to come visit you, or even go stay with them if you can get away so you can babysit and do some housekeeping so he can take care of his wife for a while. I'm a lupus patient who lived with a younger son. MY DIL thought I was a cash cow. Was getting paid to take care of me but didn't. My son was working 13 hour days so she could stay home with their kids and thought she was just messy. DIDN'T know she spent her days watching tv, eating candy, neglecting kids and me. I also paid rent. I know abt emotional abuse AND abt being told one has x months to live. I've lived thru ALL of that in my 27 yrs with this disease. One learns how one reacts to all sorts of situations, and it isn't always honorable or pretty. Her mom is probably terrified, grief-stricken and clinging to the only person she feels safe with right now. Much like a child with severe separation anxiety. It's a process and some talk therapy would help, but I'm pretty sure they know that there. Have some faith and patience, and be there for your brother, even of it's a phone call every other evening. Better yet, Skype him and the kids! Good luck.

Jocelyne wrote " SIL needs to be told she is selfishly escaping her responsibilities to her own family for the sake of someone who CAN get help from others but is too selfish to let them"

What is this 1952? How about the husband(you know men can feed kids and put them to bed) quit whining and being so selfish. Her mother is dying.

Your "escaping responsibility" comments make it sound like she went off to Las Vegas, not dealing with a dying mother.

While it is a good idea to get the AL more involved, the husband sounds like a whiner.

And if the OP doesn't live too far or could get to the location, offer to come visit and help out.

I'm wondering if the cancer hasn't metastasized to her brain, causing these changes. Is she on meds for anxiety?

If m-I-l is in assisted living then she should receive care such as bathing, changing her clothes, etc. Amy can assist as needed when she visits. M-I-L may be afraid as she knows she is dying and wants that connection with family. It is a difficult situation, Amy needs to reassure her that she will be back to visit, then do so. She needs to set limits as she is working and has a family. Amy can talk to m-I-l about family & their lives if she wants, it may help keep m-I-l in the loop with family. Maybe she feels left out in the assisted living facility.

I will talk to my brother to see who can come in and talk to them. That is a great idea. It has been tough for them, that is for sure. I just feel so bad but I have to be careful not to stick my nose in too much. I just want to be able to point my brother in the right direction. Thank you so much.

Thank you all for your advice. I have been letting my brother just talk about his issues and concerns to me. I just worry about him and his family. It has been hard on them and Amy is going through a lot. I feel bad for her and I don't want the stress to crack her. I will try to get my brother to maybe have a care person talk to them. I have gotten lots of different advice on here. It is all good and a lot to consider.