Like a good sister: warm, caring, protective, but with no romance in it at all. It describes the feeling or the behaviour, not the family fact — you can be sisterly to a friend, a neighbour, a younger colleague, anyone. The commonest words after it are advice, love, affection, concern, and a sisterly hug or a sisterly kiss. That last pair is worth noticing: people often use the word exactly to rule romance out. "She gave me a sisterly kiss on the cheek" means the kiss was kind and it meant nothing more, and the speaker usually says it a little sadly. The word feels slightly formal and a bit old-fashioned; in everyday speech people are more likely to say "like a sister to me". There is also a wider use, common in women's groups and in politics, where sisterly means women standing together and supporting each other — sisterly solidarity. It can work as an adverb too (she behaved sisterly towards him), but that sounds odd to most ears, and even native speakers avoid it.

姊妹般的；像姐姐一樣的（親切、關心、沒有男女之情）。中文常用「像家人一樣」或「把他當弟弟看」來表達同一個意思。