Partition for HUF filed by aunt against us though we never stayed together nor any HUF transactions

Hi, My grand father had 4 kids, 1 son(my dad) and 3 daughters(A,B are expired and C is alive now). A and B has 3 sons each and are alive now. My GF had gifted(through gift deed) about 8 acres of land and 2 houses to daughter C(who is alive now) in 1990, registered 8 plots on daughter A and B(both are expired now)names directly in 1992. My GF purchased a land of 15 acres on my dad's name in 1971 through sale deed. My dad died in the year 1996 and GF died in the year 2003. All daughters A,B and C have sold their properties and enjoyed their money. Now, Daughter C who is alive now, filed a HUF partition suit against us(my mother and myself) saying we are part of HUF, need 1/4th partition of the property for daughter A, 1/4th for kids of daughter B and 1/4th for kids of daughter C in 15 acres of land that was purchased on my dad's name. We dont have any partitioning deed or will by my father or grand father. My questions 1). Will the court believe or plaintiff can prove without any documents that we are still part of HUF? 2). For the property bought in 1971 on my dad's name, will the court agree this property was bought as part of joint family property and divide it among the 3 sisters of my dad with 1/4th share each? 3) will the court consider the properties given to them and since they sold their properties and asking for partition on remaining properties, will court dismiss the case of partition?