"1754: coined by Horace Walpole, suggested by The Three Princes of Serendip, the title of a fairy tale in which the heroes ‘were always making discoveries, by accidents and sagacity, of things they were not in quest of’."
Btw thanks for picking nits. New things can be learned no matter what
serendipity /ˌsɛrənˈdɪpɪti/ noun
- the occurrence and development of events by chance in a happy or beneficial way.
Seems like parent’s use is Ok.