Wow. Good luck to her.
A coach of mine does some pretty epic open water stuff (did a 72 hour swim attempt, has done some 24 hour+ ones, I think she tried to swim from Victoria to Washington state but currents didn’t cooperate - oh, and she does this all while having MS. Incredible woman).
She was saying that after a while the chafing, salt exposure, open sores you develop from being in the water so long etc are the hardest part to deal with. I can’t imagine what doing that every day, for months, would look like.
I follow her on insta. She’s so cool and fun to follow. She shares her training a lot which I like.