The Collaborative International Dictionary of English v.0.48:

goody-goody \good"y-good"y\, n.
   A person who is weakly, sentimentally, or affectedly good; a
   goody-goody person; -- sometimes used to refer to person who
   acts with good intentions but who bunglingly does more harm
   than good. The latter may sometimes be deprecatingly referred
   to as a goo-goo. [Colloq.]
   [PJC]

The Collaborative International Dictionary of English v.0.48:

goo-goo \goo"-goo\, n.
   same as goody-goody, n.. [Colloq. & disparaging]
   [PJC] Gooroo