So I have this situation where for the past 3 years of high school I’ve had a family income of around 60-70k. This year, however, it is around 250k. Should I make mention of this dramatic increase in income in the additional info section of my app or is it not important.
Not sure why you would think that AOs are interested in your parents income.
No, do not mention this on your CA.
It might be something to mention on the CSS Profile, if you are required to provide that, but it is only likely to make a difference if you can provide proof that the increased income will not continue (i.e. if it’s a one-time thing, like an inheritance).
No, it should not be in your common app.