oh dang, thanks for the update, i'm sorry it's hitting the fan right now but i understand the relief that you can stop wondering when this day will come.
I agree the realtor has a LOT of nerve to drop this at your feet. I imagine they got the impression base don what your mom said, and based on how it sure would be easiest for them if you'd step in, but please don't interpret that call as any kind of moral obligation. This is your mom's own life decisions, this is the natural and foreseeable consequences of her choices, and she has many people who can help besides yourself. like the sister and aunt you mentioned. like social services. like her church, or friends, or doctors. I understand why you are tired and I think the best thing to do right now is read "Boundaries" again and take a nap or a run or whatever refreshes you. This is someone else's life, and it sucks they're having a problem but it is NOT your problem, no matter who they give your phone number to. I don't even agree you should go down in person.
edit to add - if you do not go down, another likely person to step in with money or hands-on assistance is this new buyer. think about it. they need the house vacated, and it is in their interest to put some $ at hiring movers and a truck and a garbage bin, and helping your mom get off the property. if they didn't have this new hope of you stepping in, those are the steps they would start taking. they would arrange for the moving truck, for physical labor, and for dropping off your mom at her next place. this is, unfortunately, a bit normal for foreclosure situations. they might even give her money for a couple months rent. i'm not saying you should ask for this. i'm saying, if you step back, this is the sort of assistance that will probably spring up in your place. and that's ok!