Pledging ancestral house

Dear Sir/ Madam, We are three siblings, with me the eldest (fem) married and living separate, the second (my sis) unmarried, working and living with our widowed mother, and the youngest (bro) married and living with family at his place of work away from home. It is becoming increasingly difficult for my sister to manage home and work, and my brother has no plans to move down here and contribute to the care of mother or for house maintenance. Hence i suggested that either our brother with family move in and start living with mom and sis OR we sell off the ancestral house (which is almost in a dilapidated state, due to total neglect) and all move in with me at my house. My brother suggests that the house be pledged and the money be used to reconstruct the house. Now my question is - 1. Is it possible for my mother to pledge the property as she doesn't have repayment capacity? 3. Can the three of us siblings together do the pledging with my mother's legal consent? If not, then can any one of do it and how? 4. In short, when the property has to be pledged, is it mandatory that there be only one legal heir? 5. What are the rights of female children (both married and unmarried) in their mother's property? (My father had transferred the property in my mother's name before he passed away. Mother was a home maker, now incapacitated due to her illnesses). I shall be grateful if you could give me clear answers to my above questions. Thank you, Reena