Did Ms. Gabor wear wigs on the show or was that her real hair? I've tried to determine this but it looks like her real hair though she is known for owning a wig company.
She might not be wearing wigs, per se, but there is a lot of fake hair involved in some of her hairstyles. She is definitely at least adding to her natural hair with hairpieces such as switches, falls, pads, and updos, all of which were common in the 1960s.
You can tell in the famous shower scene that Eva's hair was actually pretty short. She didn't have enough length to manage most of Lisa's hairstyles.