Sarah Hoidahl, 23, who lives with her mother and her 15-month-old son in Henniker, N.H., appeared on DeGeneres' syndicated TV show Friday.
She described overhearing the two women, as they ordered lunch at the Concord restaurant, talking about their financial problems because the federal government shutdown was holding up their paychecks.
"I'm a waitress, single mother, I know how hard that is," Hoidahl told DeGeneres.
Asked by DeGeneres how much she netted from that day's work at Ruby Tuesday, Hoidah said she ended up with $8, not enough to pay for her gas. DeGeneres then paid the $27.75 tab in cash, ending up with a fistful of change, added a 50-inch television set -- and then called for her checkbook and paid a $10,000 tip.
DeGeneres learned about the waitress' act of kindness from a posting on a National Guard Facebook page.
Hoidah said she never expected all the attention.
"It's just crazy -- and now I'm on 'Ellen,'" she said.