Welcome to planDisney, Joanna!
On my most recent Disneyland adventure, I was in a similar situation. There were 12 people in our party and multiple Disney accounts. I was tasked with taking the lead in booking
Disney Genie+ selections. Therefore, I can tell you from experience how to do this. It's actually very simple.
Open up your
Disneyland Mobile App and then tap the three horizontal lines on the bottom right. Then tap "Tickets and Passes" and then "Link Tickets & Passes." You'll then have two options: you can either scan the barcode of the tickets you want to link, or you can manually enter the ID numbers. Once you do that, the other tickets will be linked to your account. You'll then be able to make Lightning Lane selections for anyone who has Disney Genie+.
Here's a tip: try to arrive nice and early at the theme park. The lines are much shorter first thing in the morning. You'll be able to experience a number of attractions using the standby lines. I usually wait and book my first Lightning Lane selection for around 10:30 AM. This is usually when the parks start getting busier. And since you can only make a Lightning Lane selection once per ride, you're better off using the standby lines while they're not too long.
I hope that's helpful, Joanna. Thanks so much for choosing to be our Guest.
Mike