Using molecular dynamics simulation, we perform nanoindentation simulations on a Ni-graphene model system, in which a graphene flake coats the grain boundary of a Ni bi-crystal. Material strengthening or weakening by inclusion of graphene is discussed with the help of the force needed to indent to a specified depth. By varying the depth of the graphene flake with respect to the indentation depth we identify the distance up to which graphene influences the indentation behavior. In addition, we vary the details of the modeling of the graphene flake in the matrix metal and determine their influence on the performance of the nanocomposite. Our results indicate that the modeling results are robust against variations in the modeling of the graphene flake