I’’d like to see a calculation demonstrating that the odds are higher that you defend 2♠ and beat it than that you make 4 ♥ or 5 ♣. I don’t run sims but I bet some people here can.
Also, overcalling seems more likely to keep them ...
How are Monday and Dylan irrelevant? They’re only irrelevant if we assume the names and days were not picked randomly for the problem. The irrelevant fact is “at least one is a boy” since that’s known already.