My mother is experiencing mood swings associated with dementia. We would appreciate tips on dealing with the crying?

Our mother has been in a memory care unit for almost 9 months, suffering advanced progressive dementia...vascular, Alzheimers, frontotemporal, with dispute between doctors as to whether Lewy Body is also involved
She has had a really rough ride with infections, hospitalisations, delerium, and falls out of bed and her wheelchair. Our instructions are now to only send her to hospital if she shows obvious signs of head trauma, each hospitalisation for simple falls (better described as slides) having caused her more angst than it was worth.
Although she has not had a psychotic episode for some months, she is still being quite aggressive towards the staff at times. We suggested if she does resist their attempts to lift her after a fall (she throws anything within reach, can crawl on hands and knees or shuffle along floor on her bottom to reach things), she be left to cool off before they try again. She then of course accuses the staff of putting her on the floor.
We can deal with all that plus the weird circadian rhythms, the refusal to eat, to over eat, non compliance with meds and personal hygiene, the swearing, the paranoia, the confusion, the accusations. What we are having difficulty with is the constant crying associated with her rapid mood swings.
There are two types of crying. One is more of a grimace, sometimes accompanied by constant waling which can be seriously unsettling for other residents in the unit. It is like a child having to try really hard to cry to get some attention but the act is not getting a reaction. She can be in her room when staff phone us, and she is still clearly audible.
The other type is full on tears, she says she has waves of sadness. In my case, I recount what everyone in my family unit is up to, a running account of our daily lives including our pets antics. The moment I stop for breath or to quick think another topic, off and away she goes again.
The staff have used her Memory Album, and other photo albums, to death as a distraction, they read to her, take her to the nurses station, have the usual distractions of folding socks and hand towels, putting flyers in envelopes, and so forth, all to no avail if she is in this phase with them.
With the waling grimace I just tell her she is being stupid and to stop, which she does, but that does not work with my sisters and the staff. She has always called me bossy boots, so presume her compliance has something to do with that rare memory. Hugs and reassurance from staff and family only make the situation worse.
Mother is being treated for depression and anxiety, regime constantly under review, has regular mini enemas to prevent constipation, has regular doses of mild pain killers 3 times daily plus has just had her Norspan patch dosage increased. Over the last 20 years she has had a number of TIAs, probably still having them, there is just no point in sending her for investigation beause a CT scan or MRI freaks her out. And there is no treatment anyway.
Does anyone have any credible explanation for the crying? Her GP and geriatrician say it is just part and parcel of dementia but do not explain further, not sure if they avoid the question or think it of little importance. And does anyone have any hints how we should react in case it is a form of attention seeking.