Mother still has urges, suggestions?

Let her have some pleasure at this age.

Well, good for Grandma!

Just leave her be and be thankful she doesn’t have any...umm... power tools.

Who knows - maybe it’s the secret to her healthy mind and body at 96?

Use it or loss it. Isn’t that what they say?

96 years old! God bless her!
Your daughters are adults and need to relax.
And, if they give you the fish eye, simply explain to them that you are not responsible for her behavior, even without the dementia.
Tell them to close their doors.
I think your comment "she's just horny, not sick" is absolutely priceless!

Your daughters are adults, and as such, should understand what masturbation is all about without you giving them the 'birds and the bees' talk! Why does their grandmother need a psychiatrist or medication for doing something that all human beings do, because she's 'too old' to be doing such a thing? In fact, this type of release should be helping her to AVOID medication, in reality!

I'd tell your grown daughters to mind their own business or put in earplugs when they hear something they dislike coming from her room.

Have you had the long talk with the girls about masturbation? Do they understand that it is "normal"? That would be my first concern.
My second concern, sorry, is that they can be mistaking pain and moans for masturbation. I am 78. I have a bad back, and when is is in trouble, my turning in bed half asleep may sound a bit like I once sounded for a happier reason.
If Mom has the urge and the wherewithall to still care about pleasure at her age I would be the first to say more power to her. I hope the girls don't think that masturbation is something THEY should be medicated for.
I think it is time for a sit down heart to heart with them about normal female sexual behavior.
IF what they thing is happening is indeed what IS happening (and I am afraid I am still not clear that is the case), then the only thing that is "different" is that there is not so much inhibition or even knowledge for Mom about how much noise she is making.
Get out the Our Bodies Ourselves (is that old book still about) and go through the entire birds to the bees of it all. My daughters loved that time, and laugh about it still.

Perfectly normal from pre-cradle to grave. At least shes only doing it in her room.

Does your mom have dementia? Is she aware that she can be heard? Does she care? I don't know what "normal" is, but I've not run across this in any of the 4 elderly female LOs that I manage care for. But I have read about it from other posts on this forum, even someone's formally "prudish" mom who would masturbate in the presence of others (she had dementia).

Well, you have 2 adult daughters who live with you,, what do they do when they get horney? LOL.. Tell them to turn on the ceiling fan or the radio, and hope they are still "interested" at her age! I really think this is more common than we hear. she is not trying to pick up men, just acting on her own private urges, which she has a right to do in her own room. Just as they do... How would they like it if she piped up every time they brought home a BF? I do agree she could keep her door shut,, no one needs or wants to see someone else "enjoying" themselves.. but it's part of life.