Look through the thread and you will see people showing their work and coming up with similar numbers. 40% was a rough estimate off the top of my head. Figures from a recent paystub of mine: gross income of $2700.80, net income of $1774.41. My deductions are more than just taxes, but regardless that is an effective reduction in pay of %35.31. This is a real life figure that the others may be similarly subjected to, as opposed to the numbers you get out of a calculator.
I think you’re confusing Gwynevere with Gwyndolin, a male raised as a female. I don’t think there’s any indication Gwynevere is male.