The celebrity Prim A'Donna appears to be missing from the Sims and the city Penthouses quest when she is required for certain tasks.
What can be done?
Search from Prim A'Donna inside the Sunset Mall in Simtown. The game team has been notified of this issue and is investigating it for correction in the future. We have a fix scheduled for the next update.
If you wish you can also contact support.