Do not worry!
Sleep walking (as well as sleep terrors) is found normally in young children and is associated with psychopathology only if persisting into adulthood.
Typically, this disorder involve a partial arousal from sleep during the first third of the night, in a period characterized by a predominance of the so called "slow wave" sleep.
In sleep walking, the patients become partially aroused and ambulatory; they are typically difficult to awaken and have amnesia for the events.
Most cases won't need any treatment, even if sometimes a psychotherapy directed towards reducing stress and anxiety - all of which are known to exacerbate this disorder - can be useful.
In extreme cases, low dose benzodiazepines (BDZ) are indicated and effective.