Having said all that, I'd like to share with you what I think would make up the ideal "Mom Kit" if you are already invested in Canon. Most of these items are direct equivalents of what I recommend from Nikon. You can read the reasoning behind my choices on that page.
I'd start off with the Canon Rebel XS (pictured above) which comes with the 18-55 mm IS lens. I'd add the EF-S 55-250mm f/4.0-5.6 IS for a telephoto zoom and the Speedlite 270EX for a flash. From here it gets a little trickier for Canon users than Nikon users.
Moms (as well as most photographers) love those smooth out of focus backgrounds and the ability to take pictures inside without a flash. These are both benefits of having a lens with a large maximum aperture. For Nikon-moms, the choice is easy. It seems like Nikon has designed a lens with you in mind: Nikon 35mm f/1.8. For Canon users, the choice is between two main candidates, in my opinion, and they both come with trade-offs.
- Option #1 is the 35mm f/2 which is very similar to the Nikon option, but costs $120 more (at $320.) This lens is sure to be great and well built, but may be out of the budget.
- Option #2 is the 50mm f/1.8 II which is aimed at consumers (not professionals) costing only $98. This a great deal - cheaper than anything a Nikon D40 owner can get - but the problem is the focal length. With this lens, you might find that you can't ever get far enough away from the action to get the shot you want.
So if you are a Canon owner looking at these two lenses, here's my advice: spend a day with your zoom lens set to 50mm and decide whether you can live with that focal length in the situations you would want to use a wide-aperture lens. If it seems good, go with option #2, but if you consistently feel like you need to zoom out, save up some Christmas money and hold out for option #1.