I have been thru two dog walkers. One was a friend of my sister's who failed to show up one day - so we fired her. Then I had to interview. You know who you can trust and who you cannot. Make sure they are insured and bonded. Also references as well as if they have backup if they are sick.
I swear I live by mine. Its also good because she is about 3 miles away. So shall I get locked out, get stuck somewhere, she is right there and can take care of my kids. Like having a nanny.