I'm an (almost) thirteen year old girl, and I think that Jessie is a good entertaining show, but not for all ages.
Educational Values It has some educational values, regarding family and bullying. There is also a kid named Ravi, who is from India. Some people think that he is a bit of a stereotype, because they show him to be very traditionally Indian, but he isn't. My best friend is from India, and the whole reason they watch the show is because they find Ravi very funny, and they like the references he makes.
Positive Role Models and Positive Messages: Jessie is a good, positive role model, most of the time. She teaches the kids good family values but in an entertaining way. They do have messages saying that you should always be there for family, and since three of the four kids are adopted, they all have very different personalities. Though Jessie does have a love life, it is enough for kids 11 or 12 years of age to handle.
Sexuality: There are a couple of sexual references in the show, but most kids at least 12 years old should be able to handle it. Jessie is dating a guy named Tony, and they do tend to flirt a lot. There was one episode in which they kissed, and slow danced, and there were a couple of jokes in that episode which some parents may not approve of. Over all, it is not that bad. Luke, one of the kids, flirts with Jessie a lot, and makes a couple of inappropriate comments, but nothing too serious. Anyone 12 and older should be able to handle it. And for younger kids, look at an episode guide online. They tell what happens in each episode, so you can decide whether or not your child should watch that episode. Sometimes an inappropriate reference is thrown out there, but younger kids won't know what they mean, and it rarely happens.
Hope this helped!