but if they are too large, who do they belong to? did they find other pairs in that same size when they searched her room?
It seems like I read that Patsy had bought a package for a cousin. They may have been too small for the cousin, or she just never got around to giving them to her, but they ended up with JonBenet's stuff. Patsy might not have meant for her to wear them yet, but kept them for her to grow into and JonBenet grabbed them to put on.
Rte66 seems to know more about this than I do but my understanding is that there was a fresh package of new underwear that PR intended to give to her niece (she bought it a Bloomingdales in NY in Nov). They were size 12 and JBR was size 4 to 6. JBR's drawer was full of underwear in the 4 - 6 size range. The only underwear larger than that were the size 12 underwear, which was also in her drawer (or whatever she kept them in) in a package of 7; I think.
The package of new underwear was traced and was, according to PR, brand new and sealed. A strong plastic clasp held a zipper closed on the package. Either a very strong person opened it by hand or someone opened it with scissors or knife. The kitchen knife WAS found on the washing machine right outside her bedroom.