More pictures of Bjork and Olaf.
Despite the pix, they were similar sizes!
A great way to play with these two sisters was to take a long piece of ribbon and dangle one end above one cat. The other one would then demand to join in, so you would dangle the other end above her. Gradually shorten the middle of the ribbon. Bingo, the cats could then, ahem, "play" (fight) together. It was very entertaining.