I believe that if you have a stable family, you can have as many as you want! The more the merrier!! Kids are great!
The one thing that I HATE, though is how my step-sister did it... one kid per boyfriend, never been married.. READ: four kids from four different fathers... they all miss them terribly, and can't understand.....
she's also a pisstank...
So, like I say, have 10 of the little beggars, but be careful how you have them...