Blended Families?

I often read two books at the same time, but I try to ensure that they're quite different so that I don't confuse characters and plots. This month, when I went on vacation, I hadn't quite finished Joyce Maynard's The Good Daughters (title characters Dana and Ruth). So the hardcover book got left behind on my bedside table to finish apres-trip. While traveling, I had my Kindle on which was The Weird Sisters by Eleanor Brown (featuring siblings Rose, Bean and Cordy) but I only got halfway through it on the plane home.

So now I'm finishing two books about five sisters, and to top it off, each family has a mother who's battling cancer. Both of these are very satisfying novels but I fear I haven't given either one its due diligence when I'm wondering why Rose doesn't visit Ruth or why Cordy ignores Dana. I guess I've invented my own sisters-mash-up!! Do you regularly read more than one book at the same time?