Hi, April,
I am starting my feedback with a disclaimer: I'm not sure how much is just my personal preference and style versus "the correct thing," but I decided to post anyways, on the assumption that if I say something interesting, you can try it, and if you like the results, great. If not....
I had pretty much the same reaction as Alain: overall, these are great. There are a few blown out spots, and the odd focus issue, but I have seen far worse (including on some wedding photographers' web sites, where it happened so often, they must have been doing it on purpose), and I don't find it distracting, particularly when viewing them as a group.
I would be inclined to reduce the lighting intensity, rather than changing the f-stop. The rule of thumb someone gave me once is that it is usually best to use an aperture in the middle for portraits (like f8 or f11), but you know your lens. One of the challenges with precise portrait lighting, particularly for subjects that tend to move around a lot (like children, for example!) is that they can move closer or further to the light. I am guessing that if you move the lights back a little (particularly if they are small lights as opposed to umbrellas), then the changes caused by small motions will be a little less.
Backing up versus turning down should be more or less equivalent in terms of the incident light, but will make differences in the way the shadows work: turn down = same shaped shadows, move back = different shadows. For the size of adjustments you need to make, probably not a big deal either way.
The other thing to check: are those areas blown out in the original? Or only during processing? I'm not sure about Canon, but my Nikon lets me see blown out areas in the preview image, so that is an easy way to know when it happens in the midst of the action.
Now for the personal taste section: for myself, I tend to prefer more dramatic lighting. Yours are very evenly lit, with enough variation to bring out the shapes. That's great if that is the look you want, but not my personal preference. You can see what I like in my portraits:
Portraits.
The other suggestion I have is that black & white is really good for practicing lighting. I also love it for portraits, but even if you don't, it might be worth looking at a few that way just to concentrate on the lighting.
And I almost forgot another suggestion: something that often works well with portraits is a little burning in at the corners. It can be very subtly done and still help to draw the eye into the subject.
Otherwise, keep up the great work, keep shooting, and keep experimenting.
Peter