Question about shop cosmetic

So a little bit of backstory, me and my mother just recently bought the ashes of creation alpha on steam a few days ago, but we haven’t gotten too far into the game at all. She decided she wanted to buy a cosmetic to have a unique appearance , so she bought the “Seat of Aelindor” cosmetic thinking that it was a cosmetic for her character. I see that it is a mount cosmetic , but I have tried everything to help her get it equipped and we haven’t been able to figure it out at all. My question is, how does she go about equipping the seat of Aelindor cosmetic?