There are no birds of prey in North America that weigh 20 lbs., LOL! The heaviest largest is the golden eagle and a larger female can push 15 lbs. And that's not very common. A large female red-tailed hawk may get close to 3 lbs. Same for a great horned owl.
Having said that, they can look HUGE, like they weigh far more than they actually do. And yorkie look like a snack to a large buteo. Sharp-shinned, Cooper's hawks go after birds, and wouldn't take a small dog.
Glad you're babies are okay!! Keep your eyes peeled.