Consent Witness.

Dear Sir/Madam: Subject: Consent Witness. There is a property which is ancestral. Father is not there anymore. Legal heirs are myself, mother, brother and sister. Mother and brother want sister to sign as a consenting witness and not as a vendor as they have spoken to her to give money at a later date. But, the purchaser is saying that sister signing as a consenting witness is not possible because tomorrow she may create some problem. Is it possible to create some problem after signing as a consenting witness? And, if so, what is the solution? Also, if property is not ancestral, then is it possible to create some problem after signing as a consenting witness? Looking forward to hear from you at the earliest. Best Regards, Kartheek D. N.