On this page of the guide, you will find out where to find your wife's gift, baby clothes, in Twelve Minutes.
If you've ever had dinner with the wife - and you probably have - you've had the opportunity to learn about the gift, which is baby clothes. This gift is in the bedroom - when you start the dinner, the wife goes there to take it.
It's inside the chest of drawers. You don't need it to unlock endings, but it's an item you can talk about with your wife. It is also the evidence in the dialogue explaining the mechanism and existence of the time loop. Unfortunately - in most cases, an attempt to talk to your wife about the child/pregnancy fails. Make sure you close the door, so your wife doesn't see you going through her stuff. It makes a difference whether you open a gift or talk about it when it's wrapped if you want to use it in a conversation with your wife.