My wife hates been called "luv" mainly old dudes that think they are been nice, so she calls them luv back. Maybe someone needs to be greated every morning with with a nice big smile and a good morning flower.
Also if the getting left on your own for a smoke break when busy happens, just go for a smoke break with her, or be on your phone and say something like "I don't know where Sarah went she just disappeared, oh wait I've found her outside having a smoke break, do you want me to tell her to come back inside"
As it's a uni job it's now your mission to wind her up as much as possible, don't worry about bad references or CV gaps if anything goes wrong.