Flying in Shadowlands after character transfer

My wife and I have been playing on individual accounts since about 2006. In the past year, my son, now 13 years old, started sharing my wife’s account. We decided to split my wife’s account (by gettinga 3rd account). It was easier to have my wife create the account and move her main toon because my son has collected many rare mounts and would lose them. We knew there would be sacrifices and excepted that. However, two things occurred we would like to rectify.

One, for some reason, my wife can no longer fly in Shadowlands even though she could before. She meets all requirements for flying but cannot. We would redo the process, if we could only figure out what to do.

Two, after completing the character transfer, the game said her toon name was in use and she had to choose a different name. Our server is low pop now, and she has had her character name since late 2006/early 2007 so I am assuming her name being in use is related to her own toon. How can she get her original name back? A search of WoW Armory shows the name in use on only one other server by a single other toon.