Will a child trailer weaken my bike's frame?

I have a child trailer that I've been hooking up to my steel mountain bike to pull around the little boy I nanny for on the local bike paths. I've always been reluctant to use the trailer with my aluminum road bike, but now that the days are getting so short, I want to start getting some ride time in on that bike during the day. I'd really like to hook up the baby trailer and go for some day rides before it gets too cold for the little tyke. The trailer, baby and diaper bag all together weigh 55-60 pounds. Is this kind of weight being pulled from behind going to weaken the lighter aluminum frame or am I just being paranoid about my beloved road bike?

I don't know about frames but check your rear wheel for loose spokes. I've heard of spokes breaking when you are hauling a lot of weight. Of course a little kid in a trailer is not a lot of weight.

My husband has pulled a Chariot trailer about 50 miles per week taking our kid to and from preschool for the past four years...that's a lot of trailer pulling miles! He has a Cannondale aluminum frame with carbon fork. He's never noticed any issue with the bike frame, rather it's been other parts that have worn out from pulling, like certain screws/bolts mostly related to the gearing, and of course there's wear on the brakes when you have to stop with that much weight behind you. So, it seems the components rather than the frame have taken a beating, but he's never had to replace anything really expensive, just little stuff. I'm guessing you'll be just fine.