^^^ Totally agree with that approach. ^^^
58 means you, your mom and your siblings still have four years to be all set for Mom's retirement at 62. Having a place of her own is surely a boost and a relief for your mom. Knowing exactly how much she'll have coming in each month and how much each of her children can chip in should be reassuring as well.
Discuss it in detail and then set it all on auto pay.
Hopefully, she'll settle in well - back in her home country. You can never go back home again. Things change and what was once comfortable - may prove to be less than - after she lives there again.
Just something to think about.
You may want to allow a bit of a travel budget for her to come for a visit once a year. You may want to all start to set a fixed amount a month aside so she has a good start or is set up for her first year or whatever makes the most sense.
Depending on her health and what she herself can really bring in each month for the next four years - it may make absolutely no sense for her to work past 62 - she might hit minimum SS or close to it, no matter what.
So yes, setting up her SS account online and looking at the numbers is step one. This will give you a clear picture of what she will receive based on her earnings.
If it is indeed very low, as in minimum, perhaps it makes sense to apply for her husband's SS (assuming there is/was one who worked here in the US). Even if they are divorced she is eligible to receive 50% of his SS under certain criteria - like having been married for ten years. A personal visit to the Social Security office will clarify all that - just call and make an appointment.
Or if she is widowed, she is entitled to all of her husband's SS - she can claim his instead of her own. Very easy to do, they will tell you what paperwork they want you to bring in and there is also a handy list on the SS website. I chose to do that since my departed husband's SS turned out to be slightly more than mine.
Once you have some facts and have played with the SS calculators like the one at AARP to see the results for different scenarios - and read the "Get What's Yours" book about Social Security Benefits you can make an informed decision as to how much support she may need in the future.
Setting up a Roth IRA may be helpful, even a CD/IRA might be a good idea.
Also, keep in mind if she works past 62, she still will not be able for Medicare - she must apply three months prior to her 65th birthday if she is still living in the US or there will be penalties - ask me how I know:).
The final decisions depend on her health and what she herself would like to do. I don't know of a single person who didn't crunch the numbers for months agonizing about what to do and when:)
Good luck - maybe it will all turn out much better than what you think:)