Want to put your kid on road to Millionaire Row by 21? Here’s how...

While some youngsters long to become rock stars or Hollywood heavyweights, others now gravitate towards another stripe of pop-cultural celebrity: the whiz kid who becomes a millionaire before age 21.

That’s not hard to fathom now, given the likes of Facebook’s Mark Zuckerberg and other tech hotshots. But for Susan Beacham — founder of Money Savvy Generat…