Oklahoma mom 'embarrassed' that her child's textbook once belonged to Blake Shelton

Don't take it too personally, Blake – this isn't really about you. As Oklahoma mother Shelly Bryan Parker shared on Facebook this week, she was "embarrassed" to find that a textbook she believes was once used by singer Blake Shelton in the 1980s is the same book her young daughter is using in school today. Shelton originally hails from Ada, the same town that Parker and her daughter call home. SEE ALSO: 10 times high schoolers had the most extra promposals The problem for Parker isn't Shelton, but Shelton's age – or, rather, the age of her child's textbook.  "I’m 40 and these people are my age!!!" she wrote. "Thank you to every teacher/parent/support staffer/etc. for fighting for my kids education!!! Don’t give up until education is FULLY FUNDED!!!!" According to People, Parker is a former teacher herself. "I said, 'No, that can't be,'" she told the publication. "I can't believe these books are so old. When I was in school, I wasn't using books that were 40 years old."  Parker shared the post on Wednesday amid Oklahoma's five-day teacher walkout protesting the repeal of state legislation that could aid school funding.  CNN reports that the walkout will continue into next week, unless lawmakers "pass a bill ending the capital gains deduction and the governor must veto the repeal of a hotel-motel tax bill," both of which teachers say affect funding. WATCH: This after-school program teaches kids to make robots