being an owner of all the equipt. you mentioned buying, I may be able to help. the kit lens that comes with the camera is sharp and very functional for everyday use, indoor(with flash) and out. It is an EFS lens, which means it only works with canon cropped image sensor cameras (ie: xt, xti) so if your looking to move to a full sensor camera at some point (ie: 5d etc), it wont work... the autofocus is pretty quick, and I find the zoom range to be very adequate for all the basics. I use this lens indoors with the flash for peep shots(its only a f3.5, so sometimes available light wont be a enough), and outdoors when the zoom range is appropriate. remember, the xti is a 1.6 crop, which means you multiply the focal range by 1.6 to get the true range (ie: 100mm = 160mm).
Now the 50mm, even though it is cheap and made out of plastic, is VERY sharp and focuses quickly. For the money it can't be beat. It's great for low light (indoors and out), and is VERY compact and light to the point you can't tell much of a difference between the weight of just the body, and the body with the 50mm on there.. plus the compactness(shortness), which is great for fitting the camera in a bag or backpack when space is limited. One shortcoming, IMO, is that it is 50mm, and when you multiply it by 1.6, it could become long for indoor of a house shooting. At least that's what I have found. So I just stick with the 18-55mm EF-S Lens when shooting indoor stuff with the flash if you need it.
I so far am liking the xti lots.. I have also picked up the 10-22mm efs and the 100mm 2.0, which really gives me a wide variety of shooting capability. The only other lenses I could se
I see myself getting are the EF-S 17-55mmf/2.8 IS USM to replace the kit lens (it has Image Stabil. and is an f2.
and EF 70-200mmf/2.8L USM for when I'd need something long focal wise and a 2.8 for low light stuff. the 70 200 is probably the ultimate lense for medium to large venue shooting, but you $pay$ for it.
So.. in summary.. for a beginner I think you're absolutely on the right track. Sure you can look into the Nikons which are great cameras as well as well as the sony alphas, but I can't comment as I dont own them. If you are going to shoot concerts, you can get away with what you are getting if the stuff is outdoors with the kit lense, or indoors with the 50mm 1.8, but that will all depend on the size of the venue and just how close you want to get. Indoor low light stuff you WILL need a minimum 2.8f to get sharp stuff, then it's just deciding how much focal length you need. Id recommend using the kit lense lots off the bat for the daughter taking pictures as I think you'll its versatility focal wise.
Good luck with your pending purchase.. and feel free to ask more questions!
edit:.. I was allmost going to suggest blowing off the kit lens AND the fifty and just go for the body + the EFS 17-55 2.8 IS.. but.. that lens comes in at a 1K retail which would blow your budget.
Should I get the Canon Zoom Wide Angle-Telephoto EF 28-105mm f/3.5-4.5 II USM Autofocus Lens instead of the one that comes in the kit?
This lens does *seem* to have a lot of your bases covered.. allthough Im not sure, even with the IS, whether it will perform well in the low light situations you want.. You'd get allmost that true 50mm to 160mm which is a great focal length, *BUT*, be careful of the built in flash with the lens when shooting close ( 28mm). My 10-22 which isnt all that long gets in the way of the flash.. meaning.. when wide to close to wide open, the lens produces a dark spot(shadow) on the bottom of pictures because the flash is soooo close to the body.. Dont get me wrong.. the built in flash is pretty bright and *ok*.. you might need to look into an ext flash to take close pics with a lens longer than the kit lens..