Yes Looper, Lola is a lot smaller and slighter than her sister which does seem strange as both her and her sister eat well. She was sick and nearly died a couple of weeks before we took her in and that seemed to knock her growth a bit - before that all the pups were similar size.
Maybe she's just a smaller dog? Lola's dad (in that pic) must be 50% heavier than our Tommy and they are brothers.