Having young kids means an avalanche of artwork treasures. Instead of piling them up on the kitchen counter, buy a corkboard for their room and let them pick which artwork is hung. When they bring new artwork home, they get to choose if it is "special" enough to go up on the board. Once the new artwork goes up, the old artwork that it is replacing is thrown away.
If you are really sentimental and want to be reminded of that painting of a dog/fairy in 10 years time, take a photo of the picture and then throw it out.