My husband had a rough time with that combo, but it's hard to tell if it was the drugs, or because the cancer was so advanced (recurrence on his liver after a year of remission) by the time he started that particular treatment.
Gemzar/Abraxane was his third chemo cocktail. His hair fell out almost immediately, it made him nauseous and lethargic, and affected his red and white blood counts to the point where he had to skip a week a few times. After four doses, he decided he'd had enough.
Let us know how your mom does. The same drugs work differently on different people; I'm holding out hope for you.