Google Classroom for Guardians
One of the most common questions I've been receiving is why can't guardians see their child's Google Classroom. Here is the answer from Google:
Guardians can't access Classroom or their child's assignments due to privacy laws. Guardians can only get email summaries, if your child's teacher allows it.
When a guardian accepts an invitation from a teacher, they get regular emails about their student’s work and classes. These emails, known as guardian email summaries, include information about missing work, upcoming work, and class activity. Your student’s teacher or the school administrator sends you the email invitation. After you accept the invitation, you get regular email summaries of your student’s work.
Here's a link to a Google page titled Guardian email summaries FAQ, with Q&A from the perspective of a guardian and educator:
https://support.google.com/edu/classroom/answer/7126518?hl=en