The 430EX II is a great flash. While not as powerful as the Canon's flagship flashes, it does pretty well for itself - especially in its price point.

See Speedlights.new Power Index for a comparison to other flashes. Again, pretty great bang for the buck (considering full ETTL II comparability).

The optical trigger built into your 7D's popup flash works quite well in relatively enclosed spaces, such as in a typical home. In my home I've been able to trigger my 430EX II around corners (i.e. out of line-of-sight), which is technically not supposed to happen because there's enough light generated by the pre-flash trigger to bounce into the next room. So, I've been able to get creative without the bother of cords or radio triggers, which is a nice convenience.

The 430EX II would be perfect for indoor photos of your new baby and it will give you a lot of additional capabilities that you can explore.