OP I'm so sorry this is happening to you and your Mum - it sounds awful. Get names and take notes of everything you witness and are told. Unfortunately I am also not surprised by what you've said.
My Dad was admitted into hospital a couple of months back with severe breathing difficulties - heart failure. He is a man in his eighties and while he is usually fairly independent (lives on his own, goes out and about by himself etc), at that point he had deteriorated over a few days, to the point where he hadn't eaten for nearly two of them, and couldn't even get from his bed to the loo without a lot of difficulty. (He is very proud and had tried to cope by himself so didn't contact me until he was really ill).
He was admitted to A & E and they actually tried to discharge him home after 48hrs, even though his condition was much the same (very weak, unable to even sit up in bed for long, could barely walk to the loo, too breathless to hold a conversation, couldn't eat. The staff kept on referring to his condition as 'fine' - I was so shocked. It was as if we were looking at different people, and they didn't see what I was seeing. I had to repeatedly say that his condition was not normal, and that he would not manage at home the way he was, as he lived alone. It took about 6 conversations before they decided to admit him to a different ward. He was left with an empty drip stuck in his hand for hours after it was finished, so that when he absolutely had to go to the loo, which was difficult enough (no asked him if he could manage, or offered to help), he had to drag the useless stand around with him. When the nurse took the drip away, she said she'd be back to take the needle out of his hand, that the drip had been attached to, but it was at least another 2hrs before it was finally removed, after we had to flag her down to ask again. He was just left, mostly.
On the new ward I was told that they still intended to discharge him the following day, until I repeated my concerns yet again several times and mentioned 'unsafe discharge' proceedings. That seemed to do the trick and they stopped pushing for him to go. In the end he was in nearly two weeks before he was deemed actually OK to be discharged.
Had I not been there, it looks to me very likely, they would have dumped an old man back into his flat, who (at that point), had no appetite, could barely stagger 5ft, took huge effort to sit up in bed, and all he was doing all day was lie there in silence as he was too weak and exhausted to do anything else.
The staff were busy, definitely - there was a man in the next bed who was very poorly and I think they were concentrating on him, but how anyone can reasonably expect someone in my Dad's condition to cook, shop and look after himself at home is beyond me. Yet the way they kept referring to him as 'fine' and tried their hardest to free up the bed, made me feel almost bad for making a stand! I think the pressure on staff has got to the point where quality of care is compromised in a myriad of ways, especially when it comes to perception of what is 'fine' and 'acceptable' in their patients.
Sorry to rant on but the OP is right. It was certainly a traumatic time, and wake-up call about the state of the NHS now. I spent a few days being genuinely worried that my Dad was going to be sent home to die, had I not advocated loudly and repeatedly.