Yes, that letter from the IRS is real. You could be owed $1,400.Nine million households could still be due significant stimulus money and for expanded child tax credit and earned-income tax credit payments Advice by Michelle Singletary Columnist With rent, food prices and utility bills up, many families could use some extra cash. Inflation is stressing people’s budgets big time. If you’re struggling and didn’t file a tax return this year, check your mail. Last week, the IRS started sending letters to the 9 million households who may still be eligible for several lucrative tax benefits, including the third round of stimulus payments, worth as much as$1,400 for an individual and $2,800 for couples. If you didn’t get the full amount of the pandemic-related Economic Impact Payment under the $1.9 trillion American Rescue Plan, you may be…