Welcome back to “Ask an Advisor,” the advice column where real financial professionals answer questions from real people. The topic can be anything in the world of finance, from retirement to taxes to wealth management — or even advice on advising. This week, for the first time, we’re bringing back a previous guest: the young lawyer who asked about Roth IRAs last week. This time he’s planning not for retirement, but for the children he and his wife hope to have in the next few years. Specifically, he’s wondering how to save for their education.  The cost of college in the U.S. has more than doubled since the start of…