  We study Andreev processes and nonlocal transport in a three-terminal
graphene-superconductor hybrid system under a quantizing perpendicular magnetic
field [G.-H. Lee et al., Nature Phys. 13, 693 (2017)]. We find that the
amplitude of the crossed Andreev reflection (CAR) processes crucially depends
on the orientation of the lattice. By employing Landauer-B\"{u}ttiker
scattering theory, we find that CAR is generally very small for a zigzag edge,
while for an armchair edge it can be larger than the normal transmission,
thereby resulting in a negative nonlocal resistance. In the case of an armchair
edge and with a wide superconducting region (as compared to the superconducting
coherence length), CAR exhibits large oscillations as a function of the
magnetic field due to interference effects. This results in sign changes of the
nonlocal resistance.
