Property transfer on my mother's name after my father's demised

My father died before 2005. He had not made any will for his property. My parents have 4 Children (3 daughter , 1 Son). Now all 4 are agree to transfer that property to my mother. Now we have to start that name transfer process but during that process we need sign of all 4 children on some document. At that time her 1 daughter who resides in other city, can't come to sign in person when court order to come because of her medical condition she can't Travel. So, there is any other way she can sign the document and then courier us or any other legal way to do that. Please advise me..