"Overlapping" isn't a technical term, nor is "either/or probability"; but I think they are asking whether two events are
mutually exclusive (non-overlapping, that is, they never occur together) or not (overlapping, meaning that there can be an outcome in which both events occur). The events are:
A: you meet a five-child family with exactly one boy.
B: you meet a five-child family with exactly two boys.
So the first question is, can these both be true of the same family?
Now they want to know the probability of the event "A or B" -- that is,
C: you meet a five-child family with exactly one boy or exactly two boys.
To do this, you may want to find the probability of each of events A and B, and then combine them appropriately.
Have you learned any theorems/facts/formulas about "or" probabilities? State them.
Then show us any pieces of what I've described that you either can answer, or can try. The more you tell us about what you do know, and where you are stuck, the quicker we can help.