Don't want to be a downer here, with all the nice stuff folks are saying about their roosters, but while I think there is no problem with a decision to keep this little rooster that your daughter likes, be prepared to reverse the decision if you need to farther down the road. I decided to keep two of the Freedom Ranger pullets and one of the cockrels from a flock of 35 I was raising this summer for meat and add them into my existing flock of 7 mixed heavy-breed layers. Things went well in the beginning, although my rooster Waldo (named for the fire that caused us to evacuate for 9 days this past summer) was very timid of the adult ladies. However, as he's reached his maturity, he has become pretty much of a bully. Every morning when I let the flock out of the coop he chases the girls all over the place. If he's quick enough, he grabs one and holds her down to mate. I have yet to see anything that looks like two consenting adults or any "wooing" of the hens. It's sort of disturbing. Egg production is down and one of the poor Freedom Ranger hens has a huge bald spot on her back, because the Freedom Rangers are not as quick on their feet as the others. I'm giving him another week or two to snap out of his teen-aged hormone rush and if that doesn't happen, he's headed for Freezer Camp for an attitude readjustment.
I've also know roosters who were very aggressive. My guy has been known to sneak up and peck the back of my legs, but will back down if I turn and move towards him. A rooster we had when I was a kid would run half-way across our 1/2 acre lot to attack someone working in the garden. Keep a close eye on things with your daughter when your rooster comes into his maturity. He may be one of the sweet, respectful, watchful roos that folks describe above, but please don't just assume that because he's nice now, he'll be safe around your daughter.