Do you mean - special church services w/ choral music? Or do you mean Christmas Eve Services?
As far as productions - she may like "The Singing Christmas Tree" which is an annual production here in CLT, but the dates are the 6th and 7th, and I wasn't sure if she will be here that soon . . .
Carolina Voices
For Christmas Eve Services, there are so many wonderful services throughout the metro area . . . but here is one: Carolina Strings will perform at Myers Park United Methodist Church, Christmas Eve, Candlelight service, 8:00 pm and 11:00 pm on December 24, 2008.
Here are some musical events in the area:
Charlotte Christmas Concerts - Christmas Shows in Charlotte - Holiday and Christmas Events in Charlotte
I have not attended Calvary's Christmas services, but have been told they are beautiful - here is info on their Christmas season concerts:
http://www.calvarychurch.com/site/20_218_0.cfm