Pet sitting in exchange for housing late Dec to early Jan

My sister who is very experienced caring for dogs and cats is coming to visit over the holidays and would like to pet sit in exchange for staying in a home/apt somewhere near Mountain View. Optimal dates are late December to early Jan. Dates are flexible. Her dog recently passed away and she is eager to lavish some love on your pet(s)! She can provide walks, give medications, etc. No charge, but would like use of a car.