Hi Mark, welcome to planDisney!
Congratulations on reaching a
Walt Disney World Resort parenting milestone. A child getting their own My Disney Experience account is right up there with their first ride on Big Thunder Mountain Railroad, if you ask me. I held my kids tightly during their first thrill ride experiences and I can assure you that you can have a comfortable amount of vacation planning oversight and control when living into this new norm, as well.
As long as you and your daughter are connected as
Family & Friends in My Disney Experience, Mark, you can continue to view and make plans for her. You can link her tickets and make or modify her theme park reservations. You can make dining reservations for her. During your park days, you can purchase
Disney Genie+ service and/or purchase Individual Lightning Lanes for her. As settings allow, you can view her Disney PhotoPass photos in your My Disney Experience mobile app.
As you're discovering, there are a few things you can't do for your daughter now that she has her own My Disney Experience account. You no longer manage her Disney bands, which honestly simplifies the process of linking and pairing newer models. You also can't reassign her ticket or download a Disney MagicMobile pass for her. Disney MagicMobile passes can be added to the digital wallets of eligible iPhones, Apple Watches, and Google Pay enabled Android phones. Currently, Disney MagicMobile passes can only be shared between iPhones using iMessage. The last thing I'll mention is that you can't change the character image associated with your daughter's My Disney Experience profile.
I encourage you to make this situation work to your advantage, Mark, by putting your tech-savvy daughter in charge of booking Genie+ Lightning Lanes and/or checking attraction wait times throughout the day. Teamwork makes the dream work and your planning team just got a new set of wings!
Plan magic; planDisney.
Jennifer