It's too early to tell if these kinds of numbers are "normal," or if they reflect her absence from the public eye for a month or two.
One thing we do know: Zero's numbers tend to dip when he IS in the public eye. I will grant you this, though: it's hard for someone to come back from sub-40 approval no matter what you do. It's possible---Nixon did it. But difficult.
Reagan was Governor of California from 1967 - 1975, and was often in the news dealing with all the protests in California, as well as more normal duties of a governor.