Usage patterns
〈人〉に親切にするto be kind to someone
He is always kind to new employees.
親切な〈人〉a kind person
A kind person showed me the way at the station.
〈人〉の親切に感謝するto be grateful for someone's kindness
I'm deeply grateful for her kindness.
ご親切に〈動詞〉kindly (do something) — polite expression of thanks
Thank you kindly for showing me around.