They said she shared 1,702 songs by downloading them without permission and then offering them online through a Kazaa file-sharing acount.Thomas had claimed that she did not have a Kazaa account. She was fined $9,250 (£4,550) for each of 24 songs specified in the case - the lowest the jury could have awarded was $750 (£370) per song.
"This does send a message, I hope, that downloading and distributing our recordings is not OK," said Richard Gabriel, the chief lawyer for the music companies.
Record companies have filed 26,000 lawsuits since 2003 over file-sharing, with many defendants settling out of court and illegal sharing dropping as a result.
Nevertheless, the practice has hurt sales because it allows people to get music for free instead of paying a fee to an authorised download site or buying a hard copy from a shop.Many other defendants have settled by paying the companies a few thousand dollars.
The Recording Industry Association of America said the lawsuits have reduced illegal sharing, even though music file-sharing is rising overall.