I agree, there are two points of view here. Its easy to scream irresponsibility on behalf of the daughter, but there is nothing here to base that on.
If the daughter found the dog as a stray, pregnant, she may not have been able to find a vet willing to do the surgery (depending on how far along the dog was). Or, she may not have had the heart to spay the dog after discovering she was pregnant...not every can do it. And, she may well have had people coming in to care for the animals or, perhaps even her mother said she would and then turned around and dumped them like that.
Also, you don't know how large her room was. When I was living with my mother, I had a cat, twelve rats in a huge cage, and a bunny (with a litter)...all in my room. My cat refused to leave because my stepfather's cat would kick her butt all the time. My door was locked whenever I wasn't home (and most often when I was). But my room was a modified play room that was nearly an entire floor in and of itself. My pets were happy, had room, and were very well cared for.
So yes, the daughter may have been irresponsible, bred the dog on purpose, and had them living in deplorable conditions and the mother did the right thing. Or, they could have been very well cared for and the mother for reasons of her own decided to give them away. Without more information, we really can't know for sure.