What's striking about this photo is that both children look a little sad, maybe even scared. These are not at all the emotions I see on my great grandmother's face in more recent photos. She almost always had a big smile on her face. Annie had 11 happy children of her own, a long life and marriage, and a lot of smiles. Old photos often look more somber than the reality - of course NO one could hold a smile as long as it took a camera to take the picture!
Maybe she just hadn't had her nap that day ;)