Chemo is different for dogs than it is for humans.
My previous then four-year-old dog was diagnosed with aggressive cutaneous melanoma & the treatment plan on offer was surgery plus four sessions of chemotherapy [carboplatin]
Few dogs have side effects & fewer still are so severe enough that the symptoms outweigh what could be gained.
My dogs SAILED through chemotherapy, was so relaxed he wasn't even sedated when it was administered by a drip & walked out the veterinary referral hospital following each session & hopped back into the car.
With his type of cancer the prognosis post treatment was six months to one year of excellent health, with no dog surviving for more than two years. He lived life to the full for all but FOUR additional years, & chemotherapy was anything but grueling.
If a treatment was not covered by my pet insurance cover I would take into consideration the dog's general health [cancer aside], how grueling the treatment would be, recovery period & whether or not it was in the best interest of the dog.
If it was, then I would pay for it on the zero interest credit card I keep for such an eventuality.
If you cannot finance the treatment then you have no option other than enjoy whatever time she has left & decide with the oncologist when to euthanize to prevent suffering.