For the last nine months of 2008, the 24-year-old was unable to hit the water because of glandular fever and anaemia.

Last week Zimmer proved she had shaken off her illnesses, putting in some promising performances at the titles in Hobart.

She admitted her comeback was not hard.

"It's been easier than ever because I'm more motivated than ever," she said.

"I've got a good group of friends who are really pushing me forward."

Zimmer competed in the 100-metre backstroke, qualifying fastest in her preliminary swim and the semi-final.

She was pipped by Emily Seebohm in Sunday's final.

Seebohm's Commonwealth record of 57.47 seconds was .48 of a second faster than Zimmer's silver medal time of 57.95.

Zimmer earned another silver in the 200m backstroke final on Monday with a time of 2.06.11,

Belinda Hockey won in 2:02.91.

Zimmer finished the 50m backstroke final on Wednesday with a bronze medal (27.26). Gold went to Seebohm (27.03) and Charlotte Clarke (27.09) claimed silver.

"It was a very good swim meet for me, just to get back up there," Zimmer said.

"I thought I would do quite well because I've been training quite relentlessly and I was so hungry."

After four years in Queensland, the south-west backstroke export returned to Melbourne this year.

The Commonwealth Games gold medallist is a member of the Nunawading Swimming Club where she trains with Leisel Jones.

Her new coach is Rohan Taylor.

Zimmer has set her sights on the Australian Commonwealth Games team trials in January.

Her times and placings at the shortcourse titles were strong enough to qualify for the World Cup titles in Europe in September and October.