The top 16 times from the heats advance to the semifinals tonight.
You can follow the races here or you can watch a live webcast at www.nbcolympics.com
The first heat today was at Noon EST, so Weaner should be in the pool somewhere between 12:20 and 12:35.
Weaner has also qualified for the 200 M backstroke on Friday. We wish her the best of luck as she pursues her Olympic dream.