What an odd thing to be proud of.
Whether my son grows up to be religious or not, I'd be pretty concerned if he failed at such an easy subject.
I guess the reason it doesn't bother me whether she passes religious studies is I feel there are more important things to spend her revision time on. Given a choice between, say, maths or chemistry and RS then I would advise her to lean her time towards a real subject like maths and chemistry.
I am actually agnostic on whether a god exists. I am open to persuasion. But I certainly don't believe in the man-made religious stories of any current religion. So to me it's a poor use of revision time to spend it on a made up subject. I wouldn't feel that way if they looked at spiritual matters such as "does a god exist", etc, rather than simply learning whatever a person wrote down in a Bible, Koran etc.
She spends several hours every night on revision and is currently top of the class in some of the sciences. If she had spare time then I agree that spending some of it getting an easy pass on a made up subject would be useful. But I feel that with limited time she should spend it on the more difficult subjects which will benefit her in life.
As I said, I am agnostic on religion but against state taught learning of made up man made stories.