Tracy,
There are two things that you need to do...
1 - If you deleted the user, you need to Enable/Restore her. The easiest way to do this is to change your filter to show Active AND Deleted users.
2 - From the Task where where the resource was added in the past (and entered time), you can view the Resources Panel (expand it) and view the <Resource>.State column. If this is set to Inactive, they will not be able to see it, make sure it is Active.
Sincerely,
Boris