This one I can address; take the stuff and then sell, toss, whatever! She does not come to your house, much less into your attic, basement, storage areas to know what you have done with the old stuff!

Be appreciative of the stuff (maybe even make a list of it and refer to it in the future, "hey, Mom, remember that platter with the turkey on it. . .") Keep a toy or two of your brother-in-law's that's in okay shape (or a book, something) and then wait 10 years and give it to a grandniece/nephew.

The old stuff makes great, "cheap" Christmas presents and the kids coming up enjoy seeing what their parents grew up with. I have my brother's teddy bear, yes it's slightly dirty, faintly moldy smelling (take a stuffed animal to a cleaner, see if they can clean it?) and he definitely doesn't want it and I don't know his daughter but if his daughter marries and has kids, guess what? LOL

She isn't going to remember all the stuff you take for very long (especially if you divide it up and all take different (one's own old) stuff so you can load a couple boxes at a time into your car each time you come over and then go straight to the trash with it! Find a "picture" you can stand and hang it in your bathroom :-)

I would not try to move her out of the basement, if she is comfortable there, at least not right now. I would get a dehumidifier, do some heavy duty cleaning, etc. Trying to get her to change against her desires/comfort level is probably at least as mentally unhealthy as leaving her there is physically and the body can take more punishment than the heart? Unless she herself has asthma, leave her alone for a bit and just work in a single direction at once.

My husband's ex-wife collected couches :-) and my stepson had to go down in the basement and rearrange the basement so there was (a) no room for more and (b) it thwarted that particular collecting drive (moved heavy cabinets in the "way" making pathways -- the ex-wife has major back issues so didn't have to worry that she'd mess up the rearrange.

Maybe make a short list of three things that would save money or improve her life (like the new computer) and talk to her about them before trying to implement them. If they changed her long distance, for example (and she complained to you all) then research other carriers and/or show her how she can "solve" that. Don't do very much behind-her-back, noticing stuff she hasn't mentioned; it looks like you are snooping and no one likes to feel like they are incompetent to handle their own affairs? Bring little gifts like a book of stamps or box of envelopes, a new address book and offer to help sit with her and copy addresses from an old book to the new one, make out envelopes for bills, put together and mail packages of stuff to his relatives (nieces/nephews, etc.) in the Midwest for her?

Sometimes just pick her up and take her out for breakfast at the diner/coffee shop or something on a Saturday morning; think of an "easy" new ritual or two for getting together with her? Offer to get her books, if she's a reader, at the library, etc. Get a little effortless stimulation into her life so she is out-and-about a bit more (could help her depression). Get her mental juices, imagination, flowing a bit more readily. I live in a relatively seedy, industrial area and love to think what stores I would put into a half-empty, rundown shopping center if I owned it or how I would fix up a neighborhood, etc. Play mental "games" like that as you are just driving to/from places. Take her for rides in the countryside, just driving, along enjoying good weather. Ask her about her childhood (like you're interested :-)

For the painting/wall papering, hold a little "party" to paint a room; get family and some of you all's friends she may know, 8-10 people and order pizza and get a room done that way. Bring samples of colors and wall paper home and/or take her to a store just to look (not "do" anything yet, just look). Let her choose what to work on "next", suggest she make a list of what she'd like to do with the house if time, money, effort were no problem. Get that imagination going. After Christmas I decided to change the blinds in my master bedroom and it was a one-month affair with a couple trips to the Next-day blind store, etc.; I had brochures and samples and colors to consider and had a ball, all for venetian blinds :-) I have made a little list and am having fun figuring out how to finance very tiny, but needed improvements over the next five years so when I (hopefully) can blast my husband out of this house, the fixes that will be needed for selling won't be as catastropic.

Last summer I invested in a stock for 4 months that made exactly enough that when I sold it I got a new refrigerator :-) Then I replaced my living room furniture, including getting a sleep sofa (maybe do that to get her upstairs? See if she'd like a new, inexpensive sleep sofa/futon) for the living room as my second bedroom is not sleepable due to needing to have the cat litter kept in it. I'm doing one thing every 2-3 months, under $1,000 a project, saving up and/or figuring out ways to "make" the money to do the project. Just hiring the 1-800-GOT-JUNK people and getting the old living room furniture trashed felt wonderful! I rearranged and got rid of some stuff I wasn't using (dining room table) so I got a whole lot more room and just feel freer/less stressed.