Yevamos 4:3-4

Yevamos 4:3

If a woman waiting to perform yibum inherited property, Beis Shammai and Beis Hillel agree that she may sell it or give it away and the transaction is valid (i.e., the brother-in-law has no claim). If she died, Beis Hillel say that the value of her kesubah and her personal property are divided between heirs on her deceased husband’s side and on her father’s side; Beis Hillel say they split the property she pledged as a dowry, the value of her kesubah goes to heirs on the husband’s side, and her personal property goes to heirs on the father’s side.

Yevamos 4:4

Once a man marries his deceased brother’s widow, they are a normal married couple in every regard except one: the value of her kesubah is secured by her first husband’s property and not the second husband’s.