The Penderwick sisters are a more modern group than the March sisters from Little Women, but both families are full of spunk and mischief so if you like one, you're likely to enjoy the other. Skye and Jane are my favorite Penderwicks, which probably explains why I liked the first three books better. The last two books focus more on the younger siblings who, while still fun, are a little tamer.
I sketched some more guinea pigs today anyway. It's funny how they're such shapeless beans and yet it's still so difficult for me to decide when I've drawn them properly.