Praying with my kids before bed - am I doing this right?

Hey guys, been trying to get my 5 and 7 year old to pray with me before bed each night. My 5 year old just wants to ask God for toys and my 7 year old copies everything he says. I want to teach them real prayer but I feel like I'm messing it up. Should I be correcting them or just letting them pray however they want? My wife says I'm overthinking it but I want to set a good example of what real faith looks like.