Grandfather property transferred when he was alive

* My Grandfather had 2 children’s (one is Son S1 and daughter D1) * Prior to 1990 my Father (S1) got the property in his name from my grandfather when my (Grandfather) was alive. * I don’t know exact year when my father got the property in his name. * In 1990 –– my father transferred property in my mother name. * In 1995 - my grandfather expired. * In 2005 – my grandmother expired. * From 1990 to 2015 (22 years) till now my mother is having property in her name with PANI/KATHA all title deed on her name. * Now D1 (my father sister) is claiming the property under HUF (Hindu undivided family). * Kindly Advice…Should we give the property to her? How to protect our property. Question1 – if my Grandfather’s property is his fathers (Ancestors)? Question2 – if my Grandfather’s property got from his Money (Self occupied Property) ? Question3- After 22 years of transfer to my mother, now my Grandfather daughter claiming property what about limitation period?