On June 2, 2003, at 2029 mountain daylight time, an Airbus Industrie A319-111, N910FR, owned by Frontier Airlines, Inc., and operated as flight 045, encountered turbulence during final approach into Denver International Airport (DEN), Denver, Colorado. The airline transport certificated captain and first officer, 2 flight attendants, and 97 passengers were not injured; however, 1 flight attendant was seriously injured. Visual meteorological conditions prevailed. An IFR flight plan had been filed for the scheduled domestic passenger flight being operated under the provisions of Title 14 CFR Part 121. The flight originated in Cancun, Mexico, at approximately 1553. According to a Frontier Airlines representative, the flight had been holding southeast of DEN due to thunderstorms in the area. The flight has just left the holding pattern. The pilot made the announcement for passengers and flight attendants to take their seats. Descending through approximately 11,000 feet msl, the flight encountered turbulence. A flight attendant was stowing a beverage cart and was thrown up in the air, fell and fractured her left ankle. At 1953 the METAR (automated weather observation) at DEN reported occasional lightning in-cloud, distant southeast; thunderstorm moving southeast; virga distant northeast thru southeast thru south of the station; cumulonimbus clouds distant northeast thru southeast thru south, moving southeast; rain showers in the distant southeast. Aviation Routine Weather Report (METAR) report taken at 2053 reported winds were from 160 degrees at 13 knots; visibility 10 statute miles; few clouds at 7500 feet agl; scattered clouds at 12,000 feet; agl, broken clouds at 15,000 feet agl; temperature 13 degrees Celsius; dewpoint 9 degrees Celsius; altimeter setting 29.93; virga distant east and south of the station; cumulonimbus clouds distant east and south, moving southeast.