This looks like a quick snapshot, not a thought out photo. The light over the baby's head is distracting. The colour sepia you chose makes the photo look more bland and dull. I also don't know what it has to do with the challenge.
I don't know why this family is "unexpected"? Also - they don't really look like a family in this shot - they look like 3 individuals - they are all looking in different directions and don't seem very "together". The light fitting on top of the child's head is off-putting and the background generally isn't great to look at. The lighting is nice though!
It is a cute picture... the expressions are nice. However, the composition is unflattering. Too much of the ceiling is shown and too little fo the subjects faces. I would have liked it if the people were looking at eachother in order to make it seem more like a family. The technical aspects could have been improved as well.