@Deborah Caines I am sorry for your loss.
You need to know your mother's basis in the property because you will use that figure (as a carryover basis) for the share that she gifted to you.
You also need to know the fair market value of the property on the date of death (April 2019) of your mother since her share will be stepped up to its fair market value.
Any improvements you made to the property will be added to the basis for the property, but the cost of improvements made prior to the death of your mother will be split between your share and her share (the latter of which will receive a stepped up basis regardless).
