Rights - joint registered propery

Good Morning: The current property that we live in is 2754 sq. ft , completely built and rented out. We purchased this property in Sep 2003 and it is a registered jointly in the names of Somashekar (me) and Venkatalakshmamma (my mother). We purchased this on loan and the loan is being paid by me. My mother intends to give away her portion of the property to my sister which I am not in agreement with. Reason is simple, by the time I clear the loan it would amount to 88 lakhs for a loan of 24.5 lakhs of loan taken at the time of purchase and that it is a loss making proposition to me in terms of both years lost paying EMI as well as the financial loss for the fact that I will have only half the property. I suggested that we sell off the property right now and that she can give away her portion of the money to my sister so that I can buy another property solely on my name and create an asset than paying back the loan in complete and then divide the property. My mother is not in agreement to this either. Kindly advise on how to deal with this. Is there a way out or is this just a raw deal that i have live with. Warm Regards, Somashekar