They treat her as a typical girl. Jem calls her "Angel May" to further excentuate her status as a girl. He is described as talking to her sweetly. They act like where they might be going she might be too afraid to go. I think it is in an effort to exclude her, but Scout is just like every other kid and does not want to be left out.
The boys encourage her to go home. They walk to the streetlight just fine with her, but when it comes time for the boys to consider going round back and into the Radley's backyard, they fear Scout will be a hinderance to them getting to see Boo Radley.