3 Beds in a studio unless I look at your photos just imagination says crowded. Your property isn't but instead of highlighting perfect for a couple your perfect guest you are highlighting with a kid that you are adequate but obviously not how it is designed. Max 2 Guests bur 3 beds?
You can mention in description that a child can be considered but focus on selling what you dp have available. Most couples with 1 younger child search 2 people anyways. Hoping for a discount for the child. lol
Check your amenities. It says no hot water and no essentials.