Mom's roommate's family stays all day. Any advice?

She should change rooms. And if she gets another like this one change rooms again. Her well being should not be sacrificed for her roommates.

It sucks that your mom has to move rooms and may have to again if she gets another bad roommate but she is declining because of this stressful situation and I would hate to see her keep going downhill. She sounds like a lovely lady.

Unless a person has a single room I don't think it is right that visitors are allowed to be in the room all day. Visits should be done in common areas out of respect for the other person that lives in said room.

People change rooms all the time, but the roommate's visitors need to do their visiting in the common room, not the private space belonging to two people.

Bring it up to the administration, because your mom has every right to peace in her private space. The "help me" stuff is a dealbreaker for that roommate, too. Ask to be moved, or pony up the money for a private room.

Yes.

Earplugs, for a start. Soft disposable foam ones, like they give you on flights, and your mother should ask for assistance with putting them in when she's ready to settle down for the night.

Trickier but still possible: negotiate with the roommate, and talk to the staff so that they can support with finding a modus vivendi that is acceptable to all parties. Be positive! - you say this lady is very nice, she has only just moved in, her husband must be nice too or he wouldn't be so concerned about his wife that he's there all day, and it is bound to take a little while for everyone to settle.

You can train your mother to realize that it is quite possible to say no nicely, and to ask people to allow you privacy without offending them.

Are there lounges or communal areas where the couple can spend time? Is the roommate currently bedbound, or might it be nice for her to get out a bit and see around the facility?

Is there a quiet room (like a library or similar) where your mother can have a little doze in a comfy chair after lunch?

Key things:

TALK!

For heaven's sake don't let this fester. Seize the day!

Countrymouse's suggestion of communal visits for the roommate is a good one; they can visit w/o disturbing your mother.

At any rate, I wouldn't let this continue w/o involving the admins.  Your mother is entitled to peace and quiet.

Complain to the administration. Your mom needs her rest and a little more privacy. At the very least, her roommate and roommate's spouse should "visit" in the day room and not the bedroom area.

I have never understood why SNFs and rehabs allow residents to keep their TVs blaring all freaking night! Seems like they should have a minimum requirement of shutting it off at 10 or 11 p.m. I've heard too many stories of people like your mom who had a rude roommate who kept the TV blaring all night, not giving a rip about anyone else in the room who needed sleep.

Have them move your mother to a different room. Ask the facility to pair her with a person who doesn't get many visitors in their room.

Read the contract and usually roommates are addressed there. We had a friend whose new roommate was a disturbance. Her daughter simply took the contract to the administrator and the new roommate was moved.

Is the roommate bed bound. If not it would be nice if the husband took his wife out to the common area especially so Mom could sleep. I think they are rude. Ask that the roommate be changed and explain why. This is now your Moms residence and as such she is entitled to have peace.

BurntCaregiver has a great idea.
Ask that she be paired with a roommate that gets few visitors. I am sure the new roommate would appreciate the company. Sadly, I am sure there are a few residents that have few visitors.