When IRCC sends the "Confirmation of Permanent Residence status" email asking you to confirm your details before opening a PR portal account, and every family member on the application receives the same email individually, it's not obvious whether everyone needs to reply separately.
What group members who'd been through this confirmed: Reply from the principal applicant's (PA) email address only, and include the details of all dependants in that single reply. IRCC then typically creates the portal account and case based on the PA's response, and most often sets up the case for the PA first — though in some cases it may cover the whole family from that one email.
You generally don't need every family member to reply individually from their own email address; doing so could create duplicate or conflicting responses. Stick to one consolidated reply from the principal applicant that clearly lists everyone's details.