What features of sir Percy face show that "nature had meant well by sir Percy" ?

I think this quote shows how she felt nature to have gifted her husband with rugged looks,

"But now, in the moonlight, she could not catch the expression of the lazy blue eyes; she could only see the outline of the firm chin, the corner of the strong mouth, the well-cut massive shape of the forehead; truly, nature had meant well by Sir Percy; his faults must all be laid at the door of that poor, half-crazy mother, and of the distracted heart-broken father, neither of whom had cared for the young life which was sprouting up between them, and which, perhaps, their very carelessness was already beginning to wreck."