1583 B. Melbancke (new ed.) 99 Children that be ouer younge for their studies.
1886 T. Hardy II. xi. 148 There are folk whose turn is before mine; and I'm over young, and may be thought pushing.
1998 Re: Dear Miss Demeanor in rec.arts.sf.fandom (Usenet newsgroup) 7 Oct. The problem of babies being raised by overyoung, immature mothers.