Maybe a little bit too personal, but when our sanctuary manager left, I bought her a Swarovski crystal Dog and Cat. She loved them (we both ended up crying)

Do you specifically want something that can be shared amongst the other staff? If not, maybe you could discretely enquire what her hobbies / interests are. (I always think it's nice when a person can tell that a gift has been bought with a lot of thought behind it).

JMHO