need more info

will it be dark at the venue?
can you use flash?
how far away will you be from where she will be performing?

__________________
You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.

What is your budget? Lots of choices, but also depend on how far away you are. If you are far, you will need a long zoom/tele with a large aperture because flash will not help (very expensive). If you are close enough, the 28-135mm IS is a good option, your stock 17-55 will work too. If you are close enough, an inexpensive option would be the 50mm 1.8 lens. I have found that I use that lens alot more than I thought when I bought it, a nice lens at a great price. Good luck.

I could probably go between $200-$300 and as far as how close it depends because the seats are first come first serve so getting there early is definitely a must. It will be dark in there but there will be lights on the stage. Thanks for all the assistance that has been offered so far Ekaz told me I could count on anyone on this board helping me

in low light, and not wanting to push the ISO too far for fear of getting noisy pics, you're going to either need a fast lens (2.8-4) or something with IS.

Even though your budget is only 2-$300, I would suggest either the 28-135IS or if you want to expand your budget a bit, get the 70-200F4L.

http://www.bhphotovideo.com/bnh/cont...ughType=search

http://www.bhphotovideo.com/bnh/cont...ughType=search

Both of those lenses are keepers that you'll use for a very long time, not specialty lenses that will live in your bag.

__________________
You have your way. I have my way. As for the right way, the correct way, and the only way, it does not exist.