Dax,
I too regularly fly with my son - now 11 but a regular passenger from 2 onwards. You just have to do your best to minimise the significant risks. Birdstrike through the canopy causing serious injury is massively unlikely; pressing on VFR into IMC is an obviously dangerous thing and you can avoid it in several ways. Mine is to have and keep properly current an IR(R), but I am lucky enough to fly from an airfield with an ILS. My wife is completely understanding but this has been uncomfortably close to home - Popham is so close to home base that I've actually only been twice, but it's a familiar sight.
I have, though, used this crash as an opportunity to remind my son that if what I am doing seems dangerous to him, he must say so. He is an avid watcher of Air Crash Investigation and understands a lot about heuristic traps as a result. Maybe one day he will be the one who says to me that we should get a hotel room or a train home...