I don’t know if we should push the issue of in-help or assisted living, advice?

My 87 yr old mom got really sick a year and a half ago. They were going to have to move in the next couple of months any, so my sister and I moved them to an apartment closer to us (they were about 200 miles away). Since that time both she and her husband have experienced declining health. My mom was just released from the hospital yesterday and I’ve had several conversations with different medical professionals with concerns for her safety living at home. She insists that they are fine and together ‘they manage’. Her husband is actually in worse health than she is, though she needs more help with ADL’s. My sister & I have serious concerns about there safety and feel it’s just matter of time (another heart of another fall). Someone at the hospital actually brought up assisted living or in-home help, and she's throughly confused at why they would even suggest such a thing. Do we sit back and wait for something to happen or push the subject?