helicopter parent
n. A parent who hovers over his or her children.
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Parents of millennials have been obsessive about ensuring the safety of their children, Howe said. When the first wave was born in the early 1980s, "Baby on Board" signs began popping up on minivans. They were buckled into child-safety seats, fitted with bike helmets, carpooled to numerous after-school activities and hovered over by what Howe describes as "helicopter parents."
—Don O'Briant, “Millennials: The Next Generation,” The Atlanta Journal and Constitution, August 11, 2003
This is, after all, the generation that made Britney Spears a star and turned low-cut jeans into high fashion. Also known as Generation Y or simply the children of soccer moms, these boomers are confident, achievement-oriented and used to hovering "helicopter" parents keeping tabs on their every move.
—Anthony DeBarros, “New baby boom swamps colleges,” USA Today, January 02, 2003
1991 (earliest)
Kids aren't the only ones who use slang in school. Here's some vocabulary that teachers aren't teaching:

Helicopter parent: A nosy grown-up who's always hovering around. Quick to offer a teacher unwanted help.
—Ned Zeman, “Buzzwords,” Newsweek, September 09, 1991
Paul Overberg was kind enough to suggest this phrase.