Yeah, it's a little hard to get through to Disney right now, so I thought I'd ask here if anyone has experience.
They're not ready for a legal name change. Fortunately, in this state, it's just paperwork. 10 minutes of paperwork, 6 weeks wait for your court order, then the tedious process of changing everything. Once school starts again in the fall, they'll have a student ID with their preferred name, so that's an option.
I was mostly thinking of the biometric scanners being offline (or not recognizing fingerprints) or how Universal is checking ID for everyone. I know Disney will take your picture, and use that picture in lieu of ID, but I don't know what the age cutoff is for "we expect you to carry ID" - clearly a 10 year old with an "Adult" AP wouldn't, but would be with family. A 14 year old is old enough to enter the parks alone, but unlikely to carry ID. An 18 year old is likely to have ID...
I don't think security is going to actively harass them, but they don't really look like their ID. Having to defend being Sally when they have a shaved head and their friends call them Joe is stressful, even if the ID says Sally. Likewise, having to defend being Joe, with long hair, makeup and a dress when your friends call you Sally. (All names are made up, but that's about where we are right now.)