We regift kids presents all the time; there are way too many! We don't really regift anything else. Sometimes I will give something to my parents/siblings and tell them it was a gift, but I don't want it.
How would the assistant keep the money when she regifts? I don't get it. I do think in situations like that (assistant, cleaners, etc.), people would rather have the money or a gift card. Unless I'm very close to someone, anything I buy will be random. It's awkward all-around.