(Image credit: Getty Images, with Gemini edits) Question : Our grandson just graduated from college with $45,000 in debt. I want to pay off his student loans, but my husband says we can't afford it. We're 73-year-old retirees with $2.1 million and $4,000 a month in Social Security that covers most of our bills. Who's right? Answer : You'll often hear that college graduates are drowning in debt. That may not be true for everyone, but the average student loan debt, including private loans, may be as high as $42,673 today, reports the Education Data Initiative . A balance that large could be difficult to shake for recent grads who aren't diving into instantly lucrative careers. So if you're a retired couple who's financially comfortable and have a grandson who just walked away with a $45,000 pile of student loan debt after wrapping up his studies, you may be inclined to help. From just $107.88 $24.99 for Kiplinger Personal Finance Become a smarter, better informed investor.…