Do I Need To Get Parent Permission Before Letting Teenagers Read My Book?

I am a writer working on my debut YA novel, and I'm currently in the process of getting beta readers. Basically, a beta reader is someone in the target audience who reads the book before publication and gives the author feedback on the story. Because my target audience is teens, I've found some teens (who are over the age of 13, but under the age of 18) who are interested in being beta readers for my book. How my process works is that I send them one chapter at a time via Google Docs, then they fill out a survey via Google Forms telling me their impressions of the chapter, then I send them the next chapter, etc. The survey is very simple: "What did you think of this character?" "What predictions do you have for what will happen next?" Etc. Basically my question is Do I need to have the consent of their parents before letting them take part in this process? It's not like it's a psychological study or anything, just asking questions like "Why do you think this happened in this chapter?" They're already using Google services like Gmail and Google Forms, which require you to be 13+ and have parent permission, so parent consent might already be implied here. Of course, I will urge my teen beta readers to get parent consent regardless, but should I like, refuse to let them start reading until they have consent? And can that be as simple as them ticking a box on a Google Form saying "I have spoken to my parents and they give consent for this process."? I'm in California. TIA!