Get someone with Alzheimer’s to cooperate. Any suggestions?

No drugs should be used until its found what type of Dementia she has. Each one is different and medication chosen for that type of Dementia. If a PCP is prescribing these drugs I would seek out Neurologist. PCPs know a little about everything and a lot about nothing. A Neurologist will give her a test and run labs. An MRI may be done and an EEG.

An AL is not the place she should be in. They do not have the ability to handle some with a Dementia. Memory Care is the best choice but is private pay. If she has no assets other than SS and a pension than Medicaid will need to be applied for.

Is she diagnosed with dementia?
Does she live with the daughters or they with her?
Basically there is no way on earth to get someone with dementia to "cooperate". Cooperation is part of our social contract, our inhibitions of our own wishes and desires weighed against the need for a greater good. People with dementia are "disinhibited" and they take no part in that social contract. Whether they were in their former "real life" narcissistic or not, they WILL BE when they have dementia. Thought of in another way they are losing control over EVERYTHING, their entire lives, bodies, choices, a cut at a time. They are easily enraged by both that fact and by disinhibition.
Of importance now is to be certain things are in place for safety of the future. A POA if the elder is able to still do one (must be competent in the eyes of the law), will or trust if still able. And safe placement. If no POA is possible there should be discussion with attorney or social worker about applications for guardianship. Safeguarding of financial matters is crucial. Protection of the public (no driving) is crucial.
There are a million things to address, but one day at a time and I am thankful you have sister-support. My best out to you.

Are either of the daughters her PoA? If so, that person (or persons) need to read the PoA document to see what activates the authority (usually one or 2 diagnosis of cognitive impairment if a "springing" PoA. Durable PoA does not require this). Once the criteria is met, guadianship won't be needed, just her cooperation.

The daughters will now need to educate themselves on dementia (if that's the Mom's diagnosis). I've learned a lot watching Teepa Snow videos on YouTube. I learned what dementia is, how and why it changes the person and how to better engage with them for more peaceful and productive interactions. Therapeutic fibs are a very necessary strategy.

If the current meds aren't working I would continue to work with the doctor to adjust them, as havinig to find the right combo or dosage isn't uncommon.

Please know that even if they can get the Mom into a facility, she can't be a risk to leave/wander or else she will need to move into the MC ward.

The active PoA doesn't need to get the Mom's buy-in on moving, or to where. The Mom needs a new level of care, whether she agrees or not. An opportunity may arise if she becomes agitated, aggressive, disoriented, delusional -- then call 911, and she will go to the ER. At that point she can be transferred directly into the pre-chosen facility.

For the time being, if it is at all possible to test her for a UTI, which is treatable with antibiotics, then do it to discount this infection as a source of her belligerence. I wish you success in helping to get her the level of care she needs that doesn't come at the expense of the wellbeing of her daughters.

Guardianship may be needed to enforce a move to AL.

Or wait for the opportunity : when a medical situation gets an ER admission (eg a fall or uncontrolled diabetes).

Pathway is ER - cognitive assessment - activate POA or emergency Guardianship - hospital Social Worker input - AL.

In short:
Await a crises.
Be ready to roll into action.
Have the AL pre-chosen if possible.