On a monetary note (and environmental I guess), thankfully her stuff "obsession" is usually not on purchased goods but most frequently things provided by Mother Nature herself. Wooly bears, flowers, stones, sea shells, ladybugs, worms and snakes; all treasures we've been begged to make room for. I admire her unblemished love of nature around her and her shrill scream of delight when she sees a butterfly flutter in arms reach. It has been a tough balance between her adoration for the items and the need to keep them safe and free in their true habitat.
We have had talks explaining that despite her love for the living things that if she keeps them that they will likely die and that if you really love something you want it to be free, alive and happy. First, I think she skeptically listens knowing full well that I do not want another creature in our home and weighing the remainder of my speech accordingly. It's made me aware that so often people with the best intentions sometimes are so blinded by trying to fix "the crisis of the moment" that they fail to really see the impact of their decision(s).Some things are just plain bad and cannot be debated; you litter = you should be ashamed but what about being a paper towel junkie, failing to recycle, failing to teach your children about recycling. Nearly everyone has a tough time making it through the day and getting everything they need to checked of their lists; adding one more thing to the list feels like something that's just not possible. So instead of having to worry about washing a snack container it's easier to pull out a ziploc bag.
Environmental mistakes are often made by people with these great intentions who don't mean to cause harm but they are either uninformed or blinded by tunnel vision. I guess this is where I point you back to some older post(s); one bottle makes a difference and huge changes are made by the first tiny step.
Above are just a few older posts that help to motivate everyone to recycle (no matter how small)!