I've had ones where there is only 2 years between children's ages, and another where the child is 11 and they say it is too soon. The family where the first child and second child are only two years apart, the youngest is now 4 and they are saying it is too soon.

I do have to say I think it might be best to wait a bit, as the couple with three kids has run out of food faster than the other families, even if I have bought a good amount (well over 1500 food units in fridge), and now they don't have the cash to buy more. So I guess they will have to just work harder.