Settlement Deed Cancelled by Old Age Lady

The lady age is more then 100 yrs and uneducated. She was purchased a vacant land on 1997 after that she was constructed a building in the land on 2002 and living there still now. She has 6 children (all got married), in July 2007 her last daughter approached and demand some amount for her family needs, but that time the old lady not have money, her daughter request to her that "Please I am arrange a financier for the money, please put the sign in the paper for mortgage against the old lady's property", the old lady also agreed to sign in the paper (as Left Thumb Impression only) in the registrar office, but she did not know the matter what they have typed in the document. After 9 months (March 2008) the old lady received the information of settlement deed, her daughter fraudulent the previous signed document as settlement deed documents on 2007 and mentioned the deed that 'in the prescript property is vacant land only'. After that the old lady cancel the settlement deed (reason for not take care and not support to me) directly in the sub registrar office. Now her daughter challenged the cancellation of deed in the court and she not implead the sub registrar in the suit, only one defendant is the old lady and the old lady not appear and decree passed in favour of Plaintiff on 2018 (as an Ex-parte decree) and possession taken by plaintiff with exparte decree only not any further order, now the old lady file the set aside petition and process are going and recently her harassment very high and disturb to the old lady and attacked and force to vacate the house, the old lady also approached to Police and they are filed FIR against her u/s 294 (b), 323 and 506 (1) of IPC police station. Please guide to the settlement deed is not valid and fraudulent.