advice needed, urgent!!

You say she only chases your friend's Mum's chi around the house, so I take it that's when they visit and your friend doesn't live with your mother. If that's the case I think it is that she is missing not having a chi companion 24/7. We got Brooke when she was 9 months old and I initially had to try all different foods and combinations of wet and dry foods to get her to eat at all. I spent a lot of time coaxing her to eat and often was throwing food out that she wouldn't touch. She was very clingy and got unsettled easily. If we went anywhere without her, she always sensed when we were getting ready to go out and wouldn't eat and then wouldn't eat at all for a day or so after being left alone which was never more than up to a few hours. If we had to leave her for longer we used to take her to a friend's home to be babysat. When we got Minx, who was not her sister, but an ex companion from the same breeder, she was a completely changed little girl. She eats so well, she's in danger of being a little "porky" and we can definitely see that she is the clingy one and Minx is more independant. I guess that, coming from an environment where there were about 12 chi's she bonded more with her fellow chis than her human owners. She has always been extremely affectionate with us, but definitely heaps more settled with a fellow chi.
You say your friend's chi just sleeps all the time, but when she's with the mother's chis she does perk up enough to chase one of them around the house? Could your friend's chi not stay with her mother and her chis until you get your little chi, when she'd have company?