Did she cross the line?

My mother-in-law, a "devout" Catholic (who never attends church), watches our sons during the day. She recently approached us about sending our sons to a Catholic Bible Camp that is a week long. Being that I am Buddhist, and my husband is Catholic (though he doesn't really practice it), we are raising our children to be very open minded and eclectic in their beliefs, and will support their right to explore religion and spirituality on their own as they mature. Because of the strictness of the Catholic church, we told her we'd have to think about it. We talked a little but never really said much else to her about it and eventually forgot about it. Well she said to us last week to make sure we remember that they will be going to that camp next week. My husband said to her that he wasnt aware it was set in stone, that we said we'd think about it and kind of forgot. She got a little pissy. And then he said that if it is just a casual kind of camp teaching some of the Christian beliefs, then fine, but if it is based on the strict teachings of the Catholic church, then no. She gave a very snooty "then forget it" reply. Well tonight she comes to us and says she called the church and she can not get her money back. We weren't even aware that she paid!! Especially since we never gave a final yes or no. Now she is expecting for us to be like "oh well, ok then" and I would possibly even consider it if I didnt feel she did this behind our back. I feel a complete disrespect for our authority as parents right now. What would you do?