I might be wrong about these being sold at Hallmark. But I bought my packs with a bunch of Hallmark lots, so I assume that's where they come from - at least partially.
These sticker packages each have 10 stickers. They are made to match the portraits at the front of the books, at least, Kit's are! Again, I have the Kit stickers because she's the girl I collect for the most (I need to find more of Kaya's things...).
The package is a cute little envelope, about 4x2 inches with a picture of the girl on the front. The back has miniatures of some of the stickers plus a little blurb. The stickers themselves have the cover illustrations of all six books (or a crop of the cover illustration) and four bonus pictures. The stickers are slightly smaller than the 4x2 inch envelope.
I think these are a really cute addition to a collection. I have to packs, in case I ever want to put the stickers on anything and I paid $1.50 each. I think that's a fair price - I definitely wouldn't pay more than $2 for a pack. They were originally either $3.50 or $5.50 - I forgot to look before I put them away, and I can't read the type on the photos. Oops.
Sticker grade: A - the pictures are good quality, and they're a nice size, too!