You all know Celestias "Disquise" as Sunny Sies right? Well who do you think Luna would be? Or the other members of the royal family?

wait what?

1053539 I don't think she has one, since the "disguise " is essentially just them if they looked like a normal pony. Well that's what Luna was when she was turned back to normal from Nightmare Moon and I think other ponies saw her like that so the disguise wouldn't work in the first place.

1053781 hmmmmmm... Okay