Reposting my similar post in WW thread
Sandals of Hermes
Given to Diana by Hermes, these are no longer in canon, but at one point allowed her to travel between Themyscira and the outside world.
These sandals have also been given to Artemis and Cassandra Sandsmark as they also provide the power of flight.
They could change it a bit and say special boots given by Hermes enable her to fly, but keep that ability for the next movie.