Oscar is four months old! At his four month appointment his doctor suggested we try solid food any time and for sure before his 6 month appointment. I've been more of an "only breastmilk till 6 months" kind of person but, eh, a few spoonfuls of applesauce at 4 months seems unlikely to cause permanent harm.
Feeding my baby sister her first bite of solid food felt like a very important thing when I was 8 so I wanted Biscuit to have this big sister responsibility as well. The kid has never taken a more efficient bath than when I told her after her bath she could trying giving Oscar his first bite of solid food.