The recommended efficiency cycle for when you're asleep or away is 8-10 degrees lower than your normal comfort level. For my house, I have the waking temperature set to 68 degrees, but I have it programmed to be at 60 when we're asleep or at work. There's no point heating the house fully if we're not there, or not noticing it because we're asleep.

If she has it set to a static 68 degrees, then that electric bill seems normal.