How did the collector meet earth
Collector: as you already know, I created earth so that there could still be human life in my original universe, this was luckily successful and she continued to create life for thousands of years... You would think we could use her age to estimate mine but because of certain universes having time flow differently it's sadly not that simple. Anyway, I was exploring my original universe one day and was looking at several planets that mysteriously had life, not only that but humans specifically. Suddenly, earth began flying towards me... I had seen her several times before and thought she was just a drone sent out by the planet I was observing to investigate an "anomaly"... This time I didn't teleport away, I was tired of remaining hidden from these civilizations... However instead I was greeted far differently than a bright scanner from a drone, instead a simple "hello"... She began to explain why she was here, I wasn't wrong about investigating an anomaly but she wasn't sent by any of the planets I was observing, they didn't even know I was there, after a few minutes I realized she was just like data, a robot created by me that survived the destruction of my home planet
TLDR I found earth while exploring and found out she was one of my creations. There are likely others like her that I made but haven't found yet.