Knee Replacement

My mother is H T Rukamani, 59 Years old, suffering from Rheumatoid Artheritis from past 15 years. She is not able to get up or walk.She is in a Wheelchair with so much pain. Dr Chandana Karunathilaka from Kothalawala Defense Hospital recommend to do total knee replacement for both legs. The cost of the surgery is 3400$. Im a only child and i couldn't find this much of amont at once. I request you to please help her.

Thank you
Sanduni