Well she ain't doing 20 sessions a week that's for sure.
And not sure how you got expense of $8k a month. Wtf is she buying and spending it on.
If she wanted to retire, she could have by now. She makes probably 5-10x almost tax free income and has been working for a few years now.
All that invested, she would have well more than enough to retire, and this is all conservative numbers, she probably makes closer to 200 a session and definitely works at least 15 sessions a day (she is at seduction this week 10-2am, 3 days)