Voice agents are becoming deeply integrated into the daily lives of millions of people, yet adults and children perceive and use them differently. Therefore, it is important to understand how parents and children envision the future of these agents. We enrolled 22 parent-teen dyads in an asynchronous remote community-based (ARC) method study. Each dyad consisting of a parent and a teen, participated in nine weekly activities over a period of eight weeks, followed by an exit interview. The participants discussed their desires and fears, such as those regarding agency, emotion recognition, voice characteristics and forms, the timing of their interactions, and voice agents' acting on behalf of others. The dyads appreciated the flexibility in participation, their ability to send responses privately to the researchers, their access to a channel for socializing with other participants, and the opportunity to build on ideas through sequential interactions during ARC activities. In the end, we discuss how our findings might inform the design of future voice agents and present recommendations for adapting ARC method while designing with parent-teen dyads.