No it isn’t right that in a family having three youngsters, there might be no young lady, one young lady, two young ladies or three young ladies, the likelihood of each is ¼. .

Let young men be B and young ladies be G

Results can be BBB , GGG , BBG , BGB , GBB, GGB, GBG , BGG

Then, at that point Probability of 3 young ladies = 1/8

Likelihood of 0 young ladies = 1/8

Likelihood of 2 young ladies = 3/8

Likelihood of 1 young lady = 3/8