My aunt was murdered in her building. The owner of the building had hired the killer to work in the building. We are sueing the building owner... what does case set on prove up call mean? The case has been going on for 6 months...

See this:
Prove Up Law & Legal Definition

A prove-up is basically a hearing when the case is uncontested - such as if the party being sued didn't respond to the complaint and so a judgment has been entered against them. Its purpose is for the court to agree to the settlement - in this case I would assume the amount of damages to be awarded. You have an attorney, right? He should be able to answer your questions as to the process.