Original: During the episode, Rachel demonstrates many signs from a certain topic (schools, daytime activities, etc.) and then has Leah and Alex sign—although they now sign first—alongside with a montage of many other children of different backgrounds.
Simplified: During the episode, Rachel shows many signs from a certain topic (schools, daytime activities, etc.) and then has Leah and Alex sign—they sign first now—alongside with many other children of different backgrounds.