Going with a cheaper body -- D3000 or XS?

I've decided that all I need for now (to learn on) is either a D3000 or Canon Rebel XS. I figure I'll get the kit lens, and if I get the XS I'll get the 50mm/1.8. If the D3000, then I'll get the kit lens and 35mm/1.8 AF-S. My main subject will be my almost 1-year-old daughter, so I'm wanting a good low light lens for around the house.

Is there really much of a difference between these 2 cameras? Is one superior over the other when it comes to indoor/low light use?

Thanks.