...i found her...alive...sprawled on the floor. she either fell or passed out. medics were called. she spent 2-3 weeks in the hospital, another 4-5 weeks in rehab and then the next 10-yrs in assisted living. she died a few months before she would've turned 99.
the takeaway? the 'i've-fallen-and-i-can't-get-up' devices are an absolute must for persons living alone. MIL was stubborn and refused to move closer to us. but for the neighbor her ending would've come a lot sooner.
Very similar story about my grandmother-in-law. She was "only" on the floor for 24 hours or so, but the damage was done. She couldn't live alone after that. Didn't survive much longer. Before that incident, she was pretty tough. Fought off a mugger who was after her purse, in her 90s.
Bottom line, checking in every few days just doesn't cut it. Once a day might not even be enough. I know some folks don't like the monitors, but be creative. There's a lot of technology out there. Cameras, power monitoring smart plugs, PIR (Person In Room) motion detectors, bed occupancy sensors, even toilet seat sensors. Be creative!
I'm not personally into the "smart" speakers, but that's another possibility if you're not technically inclined enough to do home automation stuff.