Oh no, don't throw it yet, the vinegar solution you used is actually the right approach, but the key step that's easy to miss is making sure it's completely air-dried afterwards, ideally outside in a well-ventilated spot, because any remaining moisture is what lets the mould come back. A friend of mine swears by following up with a coat of Osmo wood oil (it's non-toxic and child-safe) once the piece is fully dry, as it creates a protective layer that makes the surface much harder for mould to take hold again. For ongoing prevention in our Singapore humidity, it really helps to keep the kitchenette in a room with good airflow or run a dehumidifier nearby, since even "dry" play areas can get quite damp here. I'll be honest, the vinegar wipe alone may not be enough if the mould has gone deeper into the wood grain, so if the spots reappear after a thorough clean and dry, that's a sign it may have penetrated further and you'd want to assess whether it's still safe. Since this does involve your child's health and mould exposure, it's worth checking with your paediatrician too, especially if your son has been around the kitchenette for a while!