Half Full or Half Empty?

Look closely at the picture. There is a black line showing how much shower gel is left in the bottle:

You might be looking at this photo as a "bottle half full" instead of a "bottle half empty" type of scenario, but I am telling you that it's the "half empty" version, for sure. This bottle was just opened four days ago. Someone has been soaping up with wild abandon, and it hasn't been me. As you know, I am all for cleanliness (maybe too much so), but I am also for thriftiness. Even with my trips to the gym and the kiddo's non-stop running and playing, there is no way we should have used that much in four days. I am not happy with the kiddo, and I told her so--calmly, while showing her the evidence and explaining why I don't like it when she wastes things like that. I decided that I would have to ration her shower gel, dispensing it onto her washcloth myself, like I had to do when she was younger. She didn't like that, but she accepted it, probably because she knew she was going to be in real trouble if she didn't. This is the first time she has wasted so much of any product, so I'm not too concerned or upset. However, in my quest for quality products that (a) work; (b) don't contain harmful/potentially harmful ingredients and (c) smell good, I have yet to find any that meet all the criteria and are inexpensive. Sometimes $3.99 for a puny bottle of somewhat watery shower gel at Marshall's is the best deal I can find.

My grandparents were big on the saying "Use it up, wear it out, make it do or do without" (Depression-era mentality), and I'm trying to reconcile that with my concern about toxic chemicals in our personal products. However, since there will be absolutely, positively  no P&G anything in our house (questionable ingredients and a horrible track record when it comes to animal testing), you can understand why I see that bottle as being half empty.