There are several factors that you need to consider.
Folgers coffee doesn't compare to coffee that you've roasted and ground yourself. I'm not surprised that they prefer that you use less of "your" coffee than you use when using the Folgers.
Your references to grams and tablespoons are confusing.
When you use tablespoons, are they measuring spoons like you would use when baking a cake? Do you round the coffee in the spoon or do you level it flat?
When you brew a single cup, do you use the Mr. Coffee 12-cup machine, or are you using a smaller single cup brewer? There is a huge difference. The 12 cup brewers aren't meant to brew a single cup of coffee. The brew basket is too big, and the coffee grounds (2 level tablespoons) wouldn't get the right exposure to the water as it flows through them.
As with most coffee brewing, you're going to need to experiment, and have your family do taste tests, to find out how much coffee you'll need to use.