Tax Question (help please!)

My wife is currently claiming 0 allowances. She’s the only one who works and we’re about to have a baby so she’s paying for all three of us. She’s claiming 0 so we don’t owe at tax season. I always thought that no matter what, the more allowances you claim, the more you have to pay. But now I’m confused because I’ve been researching. Does it just depend on how many allowances the IRS thinks you can have? In our case, if my wife is providing for me and our baby, does that mean she could claim 1 or 2 allowances without meaning we owe more?? As long as you’re not claiming more allowances than they think you need, you won’t owe more in taxes? You’ll just get a smaller/no refund?