I'm currently working on a run and am curious what is the youngest reasonable age a person could be and exibit signs of being a technomancer, and interact with the matrix to some degree. The basic idea is that Mother's husband is a loyal corporate type (Actually more of a corporate assassin who works for NeoNET, so their marriage has basically fallen apart) and so she hires someone to help her and her son get away from NeoNET and her husband. The idea however is that the son (who is a technomancer) wants his father and has been accidentally leaving a trail that his dad can follow. (Or perhaps even talking to his dad via the matrix). The point is to make the kid not exactly aware of what is going on.
(Although It just came to me a teenage technomancer who didn't want to go with his mother, but was basically kidnapped could work too)