Just try to remember the last time when you visited shopping mall, these two kinds of apparel were put close. Do you know why?
It's the parents who are making the purchase for the children, so the parents are the actual customers. Kids are almost always shopping with their mothers. Putting the two in proximity makes shopping more convenient for the mother, and also more profitable for the store.
"Purchasing something for your child? Why not get something for yourself while you're at it?" And vice versa.