If Mom were to pass, can my siblings come and go as they please?

Does your mom have a will? If so, a statement can be added outlining what happens with the house. In my opinion, it should outline how long you have before you need to vacate the house, and, if you wish to stay and own the house, how that will be handled. If you wish to stay, perhaps your siblings could receive a larger share of the remaining estate assets in lieu of a portion of the house.

If mom doesn't have a will, get one written ASAP. Either way, see an attorney.

You could have mom stipulate in the will that although the property is part of her estate, you would have life tenant status after her death. Or you buy the house with your 25% and pay off the other 75% with a mortgage. Talk to a lawyer to get it written up so you are protected.

I am not answering your question legally, but emotionally - that just is the pits, I have little patience with non care giving relatives that feel that they are owed something.
First of all I would consult a lawyer and have some kind of document done. If your Mom is mentally sound that should not be a problem, and even if she wishes to leave things equally - she should certainly be able to stipulate that you get to stay in the home for 6 months or a year after her passing before selling the house - I think that would be more than fair since you have undertaken her care.

Do they say those things to your Mom and you - or just you?

I would sit down with mom and let her know that in order for you to continue staying and caring for her that you need to be protected. If not done already, POAs need to be done, will needs to be done before anything happens mentally or even further physically with her. I would get a right of residence which means even if she herself wanted to sell the house you have a right of residence and I don't think a new buyer would want you as an addition, no offense intended. Get these things done they are parmount, and do not waste valuable energy or time in trying to figure out your relatives, protect yourself and that means take care of your welfare too.

Definitely see an attorney. There are tax laws about the value of the house on the day she passes rather than waiting to sell. I had to touch on these things when my dad passed. It is critical that you talk to an attorney and get things in writing.

What happens to the house after her passing is entirely up to your mother. As a matter of common sense, most people want to leave their affairs in reasonable order. And although she doesn't have to tell you what she decides to do, it isn't an unreasonable question for you to ask.

Having said all that, it is of course an extremely awkward subject that many people do leave alone - and afterwards are very sorry they did. In your position, I think I'd suggest to my mother that I put her in touch with an attorney who will help her sort everything out so that she need never think about it again. I'd limit my involvement to drafting a check list of subjects that need to be addressed, and give a copy each to the attorney and my mother. Shut them in a room and leave them to it. Check afterwards that the attorney is satisfied that mother had been concentrating and was content with her decisions. For myself, look ahead and make sensible plans about what to do and where to live in the future, making sure that they were not based on any expectations about the estate.

Let's assume your mother either dies intestate or shares her estate equally between all four of you. Who has rights to enter the house will be up to the executor, whether appointed by the state or by your mother. It would be sensible and practical if it were you, but you can't force that. Let's further assume that the house will be sold immediately. I'm not going to say it's never happened - who would dare? - but I don't think in general even uncaring siblings attempt to evict their sister on the day of their mother's demise. Besides, even if your siblings might like to chuck you out instanter, houses don't clean and market themselves…

Actually, you know what? You're really crossing bridges before you've come to them. Choose your attorney with care. Think about the specifics that need to be decided on. Take it from there.

Who is the DPOA? Regardless, you need to get to an attorney asap! First visits are usually free, just go because you will be so sorry you didnt.Best of Luck!

If she doesn't have a will or POA, all children should be there when they are done. My sister went behind our backs and had a POA done and cleaned Dad out. Luckily I was the executor and she had no control after dad died.

Yes, get mom to add legal addendum regarding tenancy following her death if that is what you want. Otherwise, if it isn't stipulated in writing, sibs can throw you out, and force sale of property and even division of the estate.

Pat at home, if you were MY family, of course we would see to your needs. Legally, however, no one is forced to care for you. You would have to go to Social Services to find housing for the disabled. All families are different.