I can certainly understand why you would think that "personal" might be potentially redundant here. It adds repetitive emphasis to the sentence to distinguish what she finds and keeps as her own from the legitimate wages and tips she receives.
For her to say, "I’d get my wages, I’d get tips, and then I would get my own personal tips from finding money on the floor" reads as redundant because putting it that way is an excuse or euphemism for wrongfully keeping "the big wads of cash" that customers inadvertently dropped on the floor of the club during the course of regular business.
Claiming such funds are her "own personal tips" is disingenuous. It is not her money, not the club's money, nor was it intended as a gratuity for the staff in general or for her in particular. Found currency, like any other lost or mislaid property (e.g., a cell phone, jacket, purse, keys or wallet) should be returned to the rightful owner whenever possible. If the rightful owner cannot be identified (by reviewing security footage from inside the club or holding the funds in the club's lost-and-found department until claimed), then it should be turned over to the authorities.
For example, according to a 2014 article in Time Magazine,
"In California, there is a law mandating that any found property valued over $100 be turned over to police. Authorities must then wait 90 days, advertise the lost property for a week, and finally release it to the person who found it if no one could prove ownership."
"Theft by finding in the United States" [sic], an article in Wikipedia that deals with the history of larceny by finding in jurisprudence, primarily cites English case law on the subject from the late seventeenth to nineteenth centuries, as well as the current Australian NSW Crimes Act 1900 No 40 Part 4 Division 5 Section 124 titled, Fraudulent appropriation.
In terms of English usage, the sentence is understandably misleading, and you were right to call it out.