My DH has tried to have a discussion with MIL many times over the years about what she has in place for her future. She lives with her long-term partner but the house belongs to him. He has his own children who he presumably will leave the property to in the event that he dies first. He won't discuss his plans with us but has indicated that MIL will be ok. I assume there's a clause to say she can remain there until her death, but he won't confirm. MIL won't discuss it with her partner either so has no idea what her future holds.
The real issue for us is that she appears under the impression that she can come and live with us. It's been mentioned by her "jokingly" many times over the years. About a year ago DH sat her down and told her straight that moving in with us in the future is not an option. We thought the issue was resolved. However, we saw her recently and the topic came up again due to another relative's death leaving a bit of a mess behind. She stated that she wouldn't want to stay in her partner's home even if she legally could and that she would "just have to come and live with you". She then refused to engage when DH once again tried to explain why it was not an option.
This has left us feeling pretty bad as obviously, we don't want to have to keep telling her that we won't be having her here. It's absolutely out of the question though. I have no desire for living with MIL, let alone care for her in her dotage. We don't have space, money, or time for it either. We still have young children who will be at home for at least the next 15 years or so. We also both work full time and have no other family around that could help out. My own mother has made it clear that she has no expectations like this from me and frankly, my husband has been an utter arse at times over the years and while he's better now I have no desire to make any sacrifices to care for his mum (and let's be honest it would end up falling to me).
To clarify in case anybody asks we have had no family help over the years as we live miles from family so we are not in any kind of "debt" in that way.
Away, I guess my question is how do we broach this with MIL to make her understand that we are serious? I honestly believe she thinks that if she just waits until the situation arises we will have no choice but to take her in. Without wanting to come across as a completely uncaring bitch I would not agree to do so.