Only a member of the Trusted List can change the last name at birth (LNAB). This profile has just one Trusted List member, the profile manager. Steps to take:
#Edit the profile to describe what your sources say and provide complete reference citations. (Currently the profile is unsourced.)
#Add a comment to the profile saying that you think the LNAB should be changed to Roberts.
#Send a private message to the profile manager asking him to visit the profile, where you've proposed a change.
Whether or not the LNAB is changed, if there's evidence that people think her LNAB could have been either Roberts or Robards, make sure that the name that isn't chosen as LNAB appears in the Other Last Names field.