According to Official Guinness Records,
The lowest height for a bar under which a female has passed is 21.59 cm (8.5 in) off the floor, achieved by Shemika Campbell (USA) on the set of "Live! with Regis and Kelly" in New York, New York, USA, on 16 September 2010.video
For a complete list of 2010 records, please visit 2010 Guinness Records in United States.