Age of Khadijah

I've often heard it claimed that Khadijah was much older than Muhammad. To my surprise, I read recently that apparently there is some dispute about this, and she may have been just 2-3 years older than him. For a very quick reference, [Wikipedia](https://en.wikipedia.org/wiki/Khadija_bint_Khuwaylid) lists 555 and 567 CE as the possible birth years of Khadijah, while Muhammad was most likely born in 570 CE. I'm surprised about this because I do not recall having read any claim other than she was more than a decade older than him - admittedly, I've never had much interest in their marriage so I wasn't motivated to read up on it. **Question:** What are the most important authoritative sources on Khadijah's age, and how widespread is the interpretation that she was something like 2-3 years older than Muhammad among scholars? Perhaps a few major scholars' names on either side of the debate would be interesting. I'm looking for a Sunni perspective.