I was 7, she was 5. She moved into a house opposite me with her six older brothers and sisters. I was an only child, as my brother didn't come along til I was 10, and we became friends instantly.
We fell out when we were 14 and 12, (teen girl stuff!) and then re-ignited our friendship at 19 and 17. We were friends for another 8 years (til 27 and 25,) and went on holiday together, dated boys together, lived together for about 9 months, went on daytrips together, and went to the pub/clubs together. We drifted apart at 27 and 25 as I moved away 20 miles. Lost touch by 29 and 27.
Ten years later (at 39 and 37,) we bumped into each other by accident, and discovered we only lived 5 miles apart. This was 12-13 years ago, and we are still mates. I have moved again, and am 15 miles from her, but because of the internet and whatsapp and facebook etc, we speak several times a week. I see her once a month for a pub lunch, and we attend each others special family events.