Should i ask for money if allowing another couple to adopt our not yet born child.?

My wife is pregnant accidentally , and we have two kids already. We cant take on the responsibility and raise another right now. So out solutions is a couple we now who have been married for over ten years, and cant have children. My question is Should i ask for money ,and is that even legal. My thought is child birth cost allot when you include new clothing for my wife and her not being able to work. So I think it would be fair to ask for about 3 thousand after birth. What do you think i need all the advice i can get.