All of last year with my chicks I used pine shavings, and no matter how much I cleaned them out (which was A LOT), they stunk. Not at first, but over time they did as the chicks grew and the size of their poo grew. Plus it seemed that I was forever cleaning shavings out of the waterer and the food dish. So this year I decided to try a new method. I'm brooding mine in a plastic rabbot cage, it's rather large, and I am using potty pads for puppies under the chicks. The ones I have are by Hartz, antibacterial, and they instantly whisk the fluid out of the poo, and it dries out quickly without a single odor. I LOVE it! I change the pads daily (I use 2 at at a time) and my babies are clean, the brooder stays clean, and there are no shavings getting everywhere. I'll be using this method from here on out as long as it works. But if you are keeping the brooder in your room, you definitely need to stay on top of cleaning it. I sympathize with your mom. Pregnant women certainly do have a much finer sense of smell than non pregnant people. There was a lot of things that made me sick when I was pregnant with my girls, and a stinkly brooder could very likely make your mom sick, and make it so that she won't ever let you brood your chicks indoors again, so keep it as clean as possible! I wonder if anyone here uses DE with their chicks. DE will also keep odors to a record low. I used it in my coop all last year and you couldn't smell anything, and I had nearly 40 birds! However, I've never used it with tiny chicks, so maybe someone will have better advice on that. Good luck with your chicks though. One question though, you said you are using a cardboard box? How are you intending to keep the bottom of the box from degrading from moisture? Chicks will splash in their water, and they poop a lot. I've never used anything other than plastic to brood mine. If you have a 32 gallon storage bin somewhere, that would make a better brooder than a cardboard box. Just a thought.