By Tami Luhby, CNN Business

(CNN) -- Sarah Thomas is back at her job, but she's no longer earning enough to pay her bills.

That's because she was offered only 15 to 20 hours a week at her employer, a merchandising company, rather than her former full-time position. On top of that, her hourly pay was cut by $4, to $10.

When her air conditioning broke earlier this summer, she could only afford one for the living room, so she and her two children slept together on an air mattress.

"I can go to work, but I'm not even making enough to pay the rent," said the Gainesville, Florida, resident. "It puts you deeper and deeper into the hole."

Thomas, 38, is looking for a full-time job, preferably working from home, but the pickings are slim.

"The economy is not where it should be right now," she said.

Although the nation has added more than 9 million jobs over the past three months, many readers have told CNN that they are being offered only part-time shifts. Others say their employers have cut their pay.

In July alone, when the economy added a total of 1.8 million jobs, the number of people working part-time rose by 803,000 to 24 million.

"We added more jobs than most people expected, but the gains really were disproportionately part-time workers," said Kate Bahn, director of labor market policy at the Washington Center for Equitable Growth. "To me, that means even if workers are coming back, it's to jobs that pay less, and families will be worse off."

On a brighter note, the number of people who are working part-time jobs but want full-time work dropped by nearly 620,000.

The state of the economy is under a microscope on Capitol Hill, as lawmakers decide whether to extend the $600 federal boost to unemployment benefits.

Democrats say the job market is still weak, and laid-off Americans still need help. They want to continue the enhancement into early next year.

But Republicans point to the third straight month of job gains as a sign that the economy is recovering. They fear that continuing the $600 supplement — which, when combined with state benefits, provides two-thirds of the jobless with larger payments than they used to receive in wages — will deter workers from returning to the labor force. GOP lawmakers are pushing to cut the weekly enhancement for two months and then provide workers with 70% of their former pay.

Before the pandemic swept the nation, Betsy Kroon was talking to a hair salon operator about a full-time job as a copy writer. The company called her in July with an offer — but only for a few hours a week. She worked two hours the first week, then 10 hours, and then about five hours this past week.

Kroon, 40, says she had to move back in with her parents in North Mankato, Minnesota, because she can no longer afford her Los Angeles apartment. She's submitted resumes to nearly 200 jobs since March but only landed three interviews, all within the last month. Only one was for a full-time job — the other two were part-time. She even applied to a dozen contact tracer positions, but never heard back.

While she's happy to be working in her field, Kroon would like a job that allows her to live independently.

"I'm taking it because it's what's available at the moment," she said.