WordNet sense 1 (tolerant or lenient):

indulgent, soft

WordNet sense 2 (granting or inclined or able to grant permission; not strict in discipline):

permissive

WordNet sense 3 (not strict):

easy

WordNet sense 4 (not demanding; requiring little if any patience or effort or skill):

undemanding

WordNet sense 5 ((used of persons or behavior) inclined to show mercy):

clement