He also says "I wish I could pay off the mortgage". From what he described, he should be able to pay it off in a year or two.
Doesn't add up.
Retiring in 15 years requires quite a bit of investment every year if he wants to roughly maintain income at retirement, and many people would hope to be better off over time. Depending on how much risk he is willing to take, he might need to invest as much as $400,000 per year!
For such an early retirement he might be seeking an eventual portfolio of as much as $30,000,000 before he retires. Right now you can't count on much more than a couple of percent above inflation return on investments without taking risks that he might not be comfortable with.
Edit - actually his family status says getting married next year, and rereading the statement about the education savings he could be speaking in the future tense.