From the two devices you mentioned, this sounds more like a coincidence. There are multiple factors that can impact battery life: phone constantly searching for signal, apps draining the battery, screen brightness, etc. When you go to your battery manager, what are the top 5 apps and battery percent usage? Also, can you share the same info that your wife is seeing on her iPhone?
The first thing I tend to look at is the apps installed on the phone. Some apps stay resident and do "stuff" in the background. One app I won't have is Facebook. I use their mobile web interface. Some other apps I've found surprisingly "busy" include things like Walgreen's app. The best apps are the ones with the "EXIT" button. The more you turn off, the better. Turning off WiFi, Location Services and Bluetooth all save battery. Most phones also have battery saving settings.
Hi kayasuma! Just checking in to see how your family's battery life is doing these days. Were you able to pinpoint what was draining your batteries so quickly, or take any steps to improve the situation?