On the back of this book it says:

Up Till Now is Annie M.G. Schmidt's "collected poetry for adults" in the broadest sense, both of "poetry" and of "adults". Included, for example, are all the poems in which the leading roles are taken by the pastor, the Green sisters and Veronica the Sheep - no matter how much the original publications resembled children's books. We also find all the songs from the famous 1950s radio play The Average Family.
A unique quality of Annie M. G. Schmidt's poetry is that you don't need to learn it by heart to remember it. This is true of the "real" poems from collections like And What Else? and Domestic Poetry, but even more applicable to the songs, which have the added benefit of a catchy tune. Up Till Now also includes the songs from Bicker's Boardinghouse, the cabaret songs (thirty-nine enormously productive years), and the songs from the eight musicals with which Annie Schmidt concluded her poetical career: the oldest, Better More than Sorry, dates from 1965. Up Till Now comprises half of one of the Netherlands' richest poetic oeuvres of the postwar period. The 347 children's poems are collected under the title There!