I walk my sister's dog. Did I mess up?

Sorry for the board hop. First off, my sister is married, and I'm a job seeker. My sister went back to work starting November. They have a dog, and she asked me to walk it during the day. I took the 300k thinking of it as easy PT pay, agreeing to do it only on weekdays. But recently, whenever I go to my sister's place, I can hear the dog barking outside before I even go in. It never used to do that, but I think it developed separation anxiety. The loud barking made me nervous. Anyway, I walk the dog for an hour and a half, wipe its paws, and leave. Sometimes I play with it a bit before leaving.