It is not impossible to list all possiblities. Since each child can be either boy or girl there are possibilities: BBBBB, BBBBG, BBBGB, etc.

Rather than do that, I will note that exactly one has no girls: BBBBB. Five have one girl: GBBBB, BGBBB, BBGBB, BBBGB, and BBBBG. That leaves 32- 6= 26 that have two or more girls. Therefore, your answer will be a fraction having 26 as denominator, not 32.

It should be easy to see that there are also exactly five ways to list "four girls": BGGGG, GBGGG, GGBGG, GGGBG, and GGGGB.