You need to make the litter box more enticing for your cat to use and the clothes, less so. Which for sure means picking up the clothes in the first place to eliminate the temptation. Get a laundry hamper or throw them in the closet and close the door.
What kind of litter box do you use (covered or not?), and how many are there? If it's the same litter box that your daughter allowed to get overly "ripe", then perhaps it's time to get a new one. Also, if it's a covered box, many cats prefer an uncovered one (although there are exceptions - a few cats like covered ones better, so offering a choice might be a good idea). I'd also suggest having 2 litter boxes because many cats (mine included) don't like to urinate and defecate in the same box.
What type of litter? If it's scented, it really shouldn't be. Cat's noses are way more sensitive to odours than ours and the strong perfumes could put them off using a litter box. For now you might want to try Dr. Elsey's Cat Attract litter, which has a herbal blend added that encourages litter box use: http://www.preciouscat.com/
And finally, some links on dealing with litter box issues: