Can I use a regular harness for scooter-driving?

My dog is a boxer/lab mix. She is super smart and learns very easily. I've been running her (not to hard) attached to a 3-wheel scooter with my little brother (4) on it. He's not dead wieght, he pushes the scooter, and we only do 2 laps doen the sidewalk, so its okay. but I want to get a bigger scooter, and take her on trails with me. Is a regular harness (typically found at petsmart) okay for this? I won't be working her very hard, I just want to know if I have to get a professional harness if it's not very... professional. Thanks!