Best Friend Quotes, any good ones you've heard?

My cousin just graduated high school and we have been best friends ever since i was born. I bought her a picture frame as a grad present and i put pics of when we were little and now in it. in one of the spaces i want to put a quote about best friends or growing up or something like that. i searched on Google but i can't find anything really great. does anyone have any good ideas? thank you so much!