Island's Women (Part 1)

You've been sailing for hours and find yourself on Toggler Island. There, you meet five girls named Penelope, Quinn, Rachel, Sofia, and Tiffany. Four of the girls will toggle, or switch between lying or tell the truth each time they're asked a question. For example, if I was a toggler, and my favorite color was red, I would either lie or tell the truth the first time you ask me what my favorite color is. I might say red the first time, and blue the second time, or I might say black the first time and red the second time. The fifth girl always tells the truth, but you don't know who that is. Your goal is to find out who is the truth teller by asking as few questions as possible, and ask them to take you home. Since you don't know the route to your home, you need to figure out who is truthful and ask them to take you home because they'll lead you on the correct route, while the togglers will lead you on the wrong route. What's the least amount of questions you need to ask to be sure of who is the truth teller?