Open Trade - Pg 105 (Patreon)

A 7 year difference isn't the most drastic, but doing some little things to age her down and maintain her trades. 

Meanwhile her education is in tact. She's not the only 18 year old in this world with a degree. 

In-world rules keep her from being any younger. No one under 18 is allowed to make a trade on the market. There are exceptions for minors to use nanobots for medical issues with parental consent. But with trades largely viewed as 'elective' they are limited to 18 and above.