Jolly hockey sticks is a humorous British expression used to describe a woman or girl of a high social class who is enthusiastic in a way that annoys most people.
Some further explanations –
Used as an exclamation
(In imitations of speech associated with a type of upper-class English schoolgirl) used to express boisterous enthusiasm or excitement.
“Hurrah and jolly hockey sticks! The Royals are once again out in force for another season of one-day events”
Used as an adjective
Denoting or relating to a woman or girl having a boisterous or hearty manner regarded as characteristic of a type of upper-class English schoolgirl
“I know she’s dreadfully jolly hockey sticks, but she does mean well”
Isn’t she just the epitome of this expression? Can’t you just imagine her off for the hunt with a pip-pip, toodle-ooh, or toodle-pip? She looks to be a terribly, terribly British upper-crust old gel, don’t you know? But by George, by golly and by gosh, it is beastly that this good egg isn’t a Brit at all. Poppycock, I hear you exclaim! And alas it is true. This photo and the sitter come from France.