a nice puzzle
answer in white font 2, 2, and 9 ... there are 6 possible age combinations, only two give ambiguous sums of ages (2, 2, and 9; 1, 6, and 6) and it must be one of these or else the house number would have solved the problem in step 2; only 2, 2, and 9 gives a single 'oldest' child...