Having a baby is a huge responsibility. First you have to like, buy diapers and stuff, and then you have to worry about how you're going to make your gender reveal go viral.
Some people go the cake route. Don't go the cake route. Instead, consider something simpler, like maybe an elaborate pulley rig that will dump either pink or blue confetti when you pull the lever. Just make sure you pull the right lever.
Failed Pinterest attempt aside, we have a serious question for you guys: Are you ever going to use that fire pit? It doesn't look like it. You can probably take that and the unused herb garden in the background there and get rid of them. That's just wasted backyard space that could be used for dropping things on people's heads.