Leg pain increasing gradually. A lot.

For a few days my mom is suffering from leg pain , earlier it was in one leg and now it happens in both legs . One day she was sitting in a position and remained sitting for long .when she moved it pained a lot . Now if she sits any where for long and getup she faces problems. Earlier she was diagnosed with having deficiency of vitamin d , for few months she took the medicines but left after few time as she continue to be in good health. Also she is little overweight . She had menstrual related issues in the past like overbleeding , pain in abdomen etc . I dont know what is the reason behind leg pain but she complains that she is unable to walk when it happens. Please help and suggest . She lives alone and is working as my father is no more . I am also working but staying far from her . This issue arised little while ago . If you need any information , do reach me out . Please help or suggest any treatments .