Puppy learned to signal for potty breaks but now wants to stay outside eating everything – help!

Our 4-month-old Boston Terrier has finally started indicating when she needs to go outside (progress!), but now we're stuck in a catch-22. Once outside, she wants to stay and eat dirt and sticks all over our large backyard instead of just doing her business.

We can't supervise her constantly, but we also don't want to ignore her potty signals since sometimes she genuinely needs to go. How do we handle this without either ignoring her cues or letting her roam unsupervised eating everything in sight?

Any suggestions?