Depends on how much money you're making

Probably 2 or 3 at most. Even if your first child is very nice your second or third can have a different personality

It's impossible

to restate the question:
a + b + c = 30, where a, b and c are odd numbers up to and including 15.
When you add two odd numbers together, you get an even number.
For example, let's say x = 2n + 1 and y = 2k + 1. x + y = 2(n + k) + 2 = 2(n + k + 1). x + y has a factor of two hence x + y is even.

When you subtract an even number from another even number, you simply get an even number.
Thus one of a, b or c has to be even.
But we can only use odd numbers, hence there is no solution.

Impossible
At least, that's what I think