I agree, Tenn, that it is difficult to keep "our" Olgas straight! Context is the big clue, but occasionally even that is difficult to interpret.
Also, I agree with Bookworm re: the table smashing episode--it might well have been an episode of hilarity rather than rage.
And yes, it was only natural that the children enjoyed practical jokes and occasional rough-housing, not just because of their youthful high spirits, but also because their Danish forebearers were famous (or perhaps infamous?!) for that sort of thing!
Considering Olga, I think it a strong possibility that some--if not a great deal--of her perceived frivolity acted as sort of safety valve--i.e., a comparatively acceptable way of venting anxieties.
Finally, for those of you over the age of, say, 30

. . . think back to when you were a teenager or in your early twenties. Remember all those wild and crazy highjinks
you pulled?!
Speaking for my current situation, I know that whenever I'm feeling overwhelmed or the least bit despressed, the very best thing is for someone to tickle my funnybone or inspire my sense of outrageousness and then I'm once again a giggling fourteen year old. In fact, in many ways I think I'm a far more giddy person
these days than I was when I
was fourteen!
That's why I think Olga could rightfully be described as "the merriest of the merry"--or sulky and a bit of a loner. Some people--i.e., Tatiana?--have moderate, balanced temperments . . . . others, such as Olga, have temperments like quicksilver!