It's quite common to be apprehensive about solo flying shortly after gaining your ppl. Not as common to be that worried but still not that unusual.
Flying with a buddy is a good suggestion or flying solo but doing straight forward trips that they are familiar with. Not really in the true spirit of 'hour building' for a cpl but they aren't at that stage yet. A few straight forward trips which they are familiar with would soon breed confidence. Small steps and all that.