When you have 3, 4 or more children all the same sex and close in age it can be difficult to keep underwear and socks sorted and in the correct drawers. We all know about "Hand-me-Downs". Dealing with them can be helpful if you use a permanent marker and put 1 dot it in the waistband or tag of the underwear for the oldest child.
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When my kids were little, I had four within 5 years, the last three were girls. As the girls started wearing panties, I put their initial in the back right under the elastic.
If your underwear doesn't have sizing tags, it's a very good idea to label them yourself. It makes it easier for you to know where to place it, in which child's drawer it belongs.
I organize kids socks and underwear so they don't get bunched up together. I use the bottom half of plastic coke bottles or liter bottles of other soda to do this.
Overhead, above our washer and dryer, I had my husband install a shelf that runs the entire length of the washer and dryer. On this shelf I placed five mini laundry baskets the ones that are usually 10" x 12". I labeled each basket with a name each person in our family.
