Will I get in trouble if my dog poops or pees on someone else's Lawn ?

Technically, your dog is trespassing when it poops or pees in someone else's yard. Most people don't worry about that, but you apparently ran into to a "neighbor" who does. The neighbor could take you to Small Claims Court if she can show any actual damages (and it doesn't sound like she could). I suppose she could take you to court for emotional damages as well, but I find it hard to believe an attorney would be willing to take that case on a contingency fee.

The best thing you can do is simply keep your dog off the "neighbor's" lawn. The dog can hold it until you get to a friendlier lawn.

I'm licensed to practice law only in Indiana, and we've never met, so I can't give you "legal" advice. My answer is simply "friendly" advice based on my experience as an attorney in Indiana, my knowledge of federal and common law, and common sense. Even if you are in Indiana, employment law questions are very fact specific, and based on the limited information you provided in your post, I can't give you legal advice, and my answer is intended as general information only. It doesn't create an attorney-client relationship.