I liked that they showed Brian's pre-shadow roll struggle in the story, in game she overcomes it with her trainer's help which is a good start to their relationship.
I got night owl and the curing dream sequence involved Brian's struggle against her shadow, another great reference that was done well.
She's one of the more racesexual umas but her uncompromising ruthless attitude feels pretty fresh in a way. She really only has one moment of vulnerability when she's facing off against Rudolf and it's used to further her relationship with the trainer which was good.
I was worried a bit about the gap moe aspect but it was handled very tactfully instead of just being unbridled pandering that would go against her general persona too much, there's just enough for you to get a sense of how important they're to each other even though neither of them show it often. This career trainer also feels like he has shit together more than most of them which works with the pairing.

Her rivalry with Hishi Amazon was handled well, the Rudolf rivalry was made up by the game but it fits game Brian well as Rudolf is basically the highest peak to climb.
I didn't like how Mayano was just tacked on at the end and she's missing from the Hanshin Daishoten for some reason, big miss. I also wish the game would've tackled Brian's health issues and decline in a bigger way with you helping her overcome it, it's acknowledged in her race with Rudolf but it's not a big deal and you're required to win anyways. I don't mind the mostly pure wish fulfillment fantasy approach either, it's satisfying and fitting for the character, a good tribute to the horse's strength but I was looking for something a bit different.
Overall pretty good career, I liked it, but my thirst remains unquenched, I hope her character story episodes and main story chapter tackle some of what I've been missing from her career.