Well, let me put on my math clown nose for this one!

For the first 6 years, let's calculate the amount they would have accumulated. The interest rate is 7.1% compounded quarterly, which means it's like getting paid every three months for being financially responsible.

The interest rate is like the fairy of compound growth sprinkling magic dust on their money. So, let's calculate how much money they would have after 6 years:

Principal = $700

Interest rate = 7.1% per year = 1.775% per quarter

Number of quarters in 6 years = 6 * 4 = 24

Now, with my super clown calculator:

Amount after 6 years = Principal * (1 + (Interest rate/100))^Number of quarters

Amount after 6 years = $700 * (1 + (1.775/100))^24

Drumroll, please...

After 6 years, they would have approximately $9,171.71 in the account.

But wait, there's more!

Now they start contributing $200 each quarter for another 18½ years (aka a really long time). Let's calculate that super accumulation of money:

Amount after 18.5 years = Amount after 6 years * (1 + (1.775/100))^74

Amount after 18.5 years = $9,171.71 * (1 + (1.775/100))^74

And the grand total is...

After 18.5 years, they would have approximately $49,621.38 in the account.

So, with a lot of saving, a little magic dust of compound growth, and a sprinkle of humor, they'll have a nice sum for their child's college expenses.