Different parenting styles??!!??!

Just wanted to start this off by saying I've never liked my brother in laws wife. She is the kind of person that'll spend all kinds of money on things she doesn't need and then whine that she has no money. She had to buy a trampoline for her house and 2 days later was demanding to know why we haven't brought our son over to jump on it. What started our recent fight was that she paid for our son to join soccer and got him soccer stuff for his birthday. We warned her that she could be wasting her money, Liam is only 7 and has never played on a team before. He could play half of one game and decide he hated it. Despite our warnings she bought the stuff anyway and Liam was excited to play. The first game came around and we could tell Liam wasn't feeling well but he wanted to try. Halfway through practice he just wasn't into it and wanted to quit. We told him he could if he wanted, we're not going to force him to play. Needless to say she was not happy about it and said we should've made him play anyway. She even asked if I could get a hold of the coach and get her money back since he was not going to play. I reminded her that he might not have wanted to play and paying for it could be a waste. She kept getting snippy although I was being polite and even went as far as posting shit on Facebook. I can't stand this woman and how she was demanding we make him play even though he wound up with a 102 degree fever. Have any of you ladies dealt with someone like this?