MDE - how to link 2 accounts?

Help!

My dad has an MDE account for him and my mum. My sister has an MDE account for her, BIL and kids. Both have tickets linked and have started making FPs for their upcoming offsite trip.

They want to link them. My dad tried to do this by just adding them by name/age to his. But when he tries to make FP for all of them, it tells him that my sister’s family have tickets linked to another account, which they do.

I’ve never needed to link accounts, so I’m clueless!!!

Thank you in advance for any advice - the simpler the better!

Somebody may correct me, but if I remember correctly it’s under “Family & Friends” in his account. He has to add the email address of your sister’s account and she will get an email to confirm that the accounts are linked.

Thanks, I knew it had to do with email addresses but didn’t see anywhere to do it!