Transfer of ownership on death of original owner

Mr X bought a one BHK Flat in 1986. Nominations for the same were 50% to Mrs X, 25% to Son & 25 % to Daughter.

Mr X passed away in 2007 - in 2008-09, on consent of the Son & Daughter, the Share Certificate was transferred to Mrs X.

Can Mrs X sell the property? If conditional, what are the next steps required for Mrs X to be eligible to sell the property?