How does one nun have 90 points after 3 strikes, and another have 89 after the same 3 strikes?
In bowling, a strike is worth 10 points, plus the value of your next two throws, so the maximum value of a strike is 30 points. Half-bangs got a strike on 3rd frame, which is worth 10. She then got a strike on 4th frame, bringing the value of her 3rd frame strike to 20. Then on 5th frame, she bowled a 9 on her first throw, bringing the final value of her 3rd frame strike to 29 points.
The scoeboard is technically in error, as half-bangs' 6th and 7th frame scores should not yet be penciled in.