Oh, I'm sure that show-jumping costs her a LOT of money.
At her level the prices are ridicously small (maybe 100 euros) and she doesn't even clasify for them because her results are not very good. Also at her level sponsorship is unexistant (of course, she may get some sponsorship that other riders woul d never get because of her name, but not enogh)
If you take into account not only that she has to feed her horses every month and that she is paying a top trainer, but the very high entrance fee you have to pay to take part in the competitions she is entering and the transport of the horses (some times to remote places like Brazil) .
And she buys horses! I kind of remember that GI JOE doesn't belong to her and she's just her rider, and I don't know about Troy, but she certainly owns Tintero and that's not a cheap horse.
No way she is making money out of showjumping. She must be expending an awful lot of money on it.
Also, having a look at her last pics with Troy... No matter how much Rozier keeps repeting that she is very talented it is obvious that she is not. Rozier has to say it because she is her most popular client and is getting a lot of money (where would he find another amateur client ready to take him to all the Global Championship towns?) and popularity from her but the girl is certainly not a talented horsewoman.
Her results, with the horses she owns are very poor, and in videos and pics you can easily see how much she lacks. Her balance does not seem great which is no wonder since her legs are often too forward. And it really seems that she has a hard hand (no wonder, the way she holds the rains!) because too often her horses look unconfortable at the mouth and appear fighting her hand in pictures.
My guess is that she will keep on riding this often for a couple of years and then she will get bored and quit. But of course I could be wrong.