For those who worry about such things, the orphan rule has now been eliminated. If you don't know what an orphan is, it is: A page may not end with a single line from a new paragraph.
Now it may.
This is from The Chicago Manual of Style, 16th Edition, Sneek Peeks and Retired Rules.
Personally, I never worried about orphans anyway. Widows, however, are a different story. I do try to rework those if they are not at least 3/4 of a line.