1099-B statements do not reflect basis stepp up to the values at the time of death. How do I file my mother's tax return this year and avoid the gains on the account?

My mother's cost basis was to be updated to the values at the time of her dearth in August of 2017.  However, the 1099-B reports that I received ignore this.  How do I use the stepped up basis to the values at time of death to avoid taxable gains on her taxes for 2017.  Do I ask for restated 1099-B's of can I reflect this in Turbotax?