welcome to the healthcare magic,defenately osteoarthritis
is an age related process and causes much pain and restricted mobility of knees with swelling ,is she overweight
,which will have again a bad impact on the affected knees ,you should continue giving shelcal
along with aglass of milk without cream daily,dont let her sit on the floor ,ask her to use chair.
you can start homeo medicines ,it will have a better results and causing no e\extra harm to the body