Originally Posted by
Camilo
Take it back and have it re-adjusted. If your service included new shift cables, the most likely culprit is the cables settling in ("Stretching"). But if you paid for service, get the service you paid for.
Barring that, go to a Park Tool instructional video about adjusting rear derailleur. Folllow all the steps, no short cuts. You'll learn that it's easy.
It’s easy in a stand. Much less so without one. That’s kind of the point of the thread. She had watched videos.