The main thing is to get the Monday of the current week.
How I would do it:
Add two custom properties to the Calendar component
Expression for currentMonday
addDays(midnight(now(0)), (2-getDayOfWeek(now(0))))
Expression for daysBetween
daysBetween({Root Container.Calendar.currentMonday}, midnight({Root Container.Calendar.date}))
Expression for Button Enable:
{Root Container.Calendar.daysBetween} >= 0 &&
{Root Container.Calendar.daysBetween} < 14
You could get away with incorporating the daysBetween function as part of the button enable, but I like to have a visual of the value.