Yes, arthritis can be cured by ayurved. In ayurveda it is termed as Amvat where ama is undigested intermediate metabolites mixed with vitiated vata forming the disease. So measures to cure alma - indigestion and to pacify vata are necessary. Early morning take Ginger along with jaggery. She can apply  borage oil / Dashag lep / pind tail  over the affected area . Take proper medicines by authentic ayurvedic doctor. Ayurvedic Panchakarma therapy will be very effective to reduce severity. Along with all this, she has to follow some do' s and don't. Avoid cold in any form. Avoid overuse of legumes and pulses except moong. Take hot fomentation daily 2-3 times after application of proper oil.

Your mother problem is permanently cuer by ayurvedic medicine treatment in one month

Two types of artritis are there one is osteo artritis and other one is rheumatoid artritis. If you have developed any structural deformity it is difficult to come back to normal state. But pain and other symptoms can be cured by ayurvedic medicines along with panchakarma treatment.