tutelary

When a minor is involved, tutelary powers frequently accompany powers of attorney.

My uncle is always happy to discharge his tutelary responsibilities towards me.

She loved him so passionately, and he was so godlike in her eyes; and being, though untrained, instinctively refined, her nature cried for his tutelary guidance. And thus, though Tess kept repeating to herself, 'I can never be his wife,' the words were vain.