Mom can't or won't answer phone/medical alert. Any suggestions?

Mom lives alone, is 90, doesn't walk well so uses a walker (most of the time.)

She's fallen a few times. Has medical alert, the wristband, which worked well until about 6 months ago when she fell & passed out, so didn't press the button.

So we got the medical alert upgrade, the pendant, to NOTICE when she falls.

Well she's accidentally triggered it 4 or 5 times. She has the medical alert box in her bedroom, plus a phone w/answering machine in the bedroom and another phone in the living room.

When it goes off and they call her through the box or phone, she usually doesn't answer. Says she doesn't hear it. Doesn't want to check her voice messages, though she will respond if she hears one of my sisters hollering at her through the speaker.

My sisters and I think it's a combination of things - her hearing is getting worse, she doesn't move very fast, and she just doesn't care anymore.

Both of my sisters live within 10 minutes of her (I live a couple of hours away), but we're hoping there are better options. My husband was thinking of something like a two-way radio; but even if that's a good idea, I don't know if she could learn how to use it, or WOULD.

We hate to move her out of her home just because she won't answer the phone, but we're kind of at our wit's end. There are other signs too, that she doesn't care or doesn't remember. Will wet her bed, then just hang the wet pad and wet nightgown up to try - doesn't care that they're dirty. She used to eat cereal in the morning, and now she doesn't. We think it's too much work for her to go back & forth to get the milk, get the cereal, get the bowl, etc using her walker.

Anyway - any suggestions?

Thank you SOOO much.