Bert Stafford - Bert Stafford's birth

I am trying to find out more about Elizabeth Tarvin Stafford, Bert's mother. Her tombstone and all of the information I've found, shows that she died in 1879. However, Bert was born in 1881. Does anyone have any clarifying information on any of this?
TIA!
Jennifer Stafford Culp
@Jennifer Leigh Stafford