The trick is: land yards in your area to make the ride worth it. And get a rope, and wedge the weed eater on top (bottom up) so that it hangs on the push-mower’s handle. Then you can just tie a rope to the bike seat beam and it’ll roll along right behind you without issues. That was the best money I made per hour for a long, long time.
Ironically, I lasted one week at babysitting. A 7-year-old running around the yard naked and screaming? Then when they added another one - nope, too much. Plus, the hourly rate was horrible. Back to mowing for me.