Jennifer Lopez was in long pants and a shirt yesterday on the hot Atlanta set of What to Expect When You're Expecting. She was able to break from her work, though, to say hello to her visiting children, Max and Emme Anthony. The trio is fresh off a long weekend in Miami, where they celebrated Jennifer's 42nd birthday Sunday with a party on a yacht. Missing from this year's celebrations was Max and Emme's dad, since Marc Anthony and Jennifer announced their plans to split earlier this month. Jennifer is nonetheless sticking to her busy schedule, first flying for a show overseas and now getting to work on her new movie.