What are sisters for?

I had an opportunity a few weeks ago to encourage a "little sister" in the faith. She was having a rough week, and I simply encouraged her to make her devotions a priority. Then I had a sister just this weekend ask me if I was okay. She had noticed that I just seemed a little down. She listened as I shared how I've been a bit overwhelmed, and she encouraged me to keep on trucking. But as I've been replaying and comparing these two situations, I began to wonder, "What are sisters for?" And here's what I came up with:

Sisters are for driving you crazy and making you mad. They are for telling you when you are being a brat, or when you're being just plain ridiculous. They're also for cheering you on when you're doing something well, or something worthwhile. They are for knowing when you're a little "off your feed" and asking what's up. And then for listening while you spill your guts-- and maybe more than a few tears. They are for laughing with you and crying with you, and mostly for just walking with you through the ups and downs of life.

(I looked for verses that talk about sisters, but didn't find what I was looking for, so...you could insert "sisters" for "brothers" in these verses.)

Finally, brothers, rejoice. Aim for restoration, comfort one another, agree with one another, live in peace; and the God of love and peace will be with you.
2 Corinthians 13:11
 
For you were called to freedom, brothers. Only do not use your freedom as an opportunity for the flesh, but through love serve one another. For the whole law is fulfilled in one word: "You shall love your neighbor as yourself."
Galatians 5:13-14