“Why has my child started sleepwalking?”

Sleepwalking can be normal but not always. It depends on different aspects of the situation (frequency, other behaviors during sleep etc). It’s better to discuss with your child’s pediatrician.

There’s really no reason to rush to a doctors office at this point. This is not an uncommon sleep issue in adolescence. This occurs in deep sleep and they tend to have a good bit of deep sleep at this age. Safety is the primary concern. I would simply monitor for now and try and avoid nights of sleep deprivation which will then cause more sleep The following night having more sleepwalking then.