Hi, Scandi. I think that she made a single call to 911 that lasted 23 minutes. The three phone calls were to her driver, who was not her pimp. Apparently, no one was interfering with her calls.
Brewer left her in the house while he went out to get the driver, because he wanted her to leave. When they came back, Shannan was on the phone near the kitchen. (She is also reporting sitting in the livingroom.) A person who feels endangered inside a house would not remain in the house even after their own driver had arrived to bring her home.The driver became exasperated by her behavior and left the house before she did.
Web sleuthers want to find clues that point to culprits, but in this case, Shannan's own history has to be taken into account. She wasn't just an average young woman; she was a woman who was bipolar and had problems with cocaine and prescription drugs. There are some reports that, like other people with bipolar disorder, she was often averse to taking her medication and it seems probable that, like many of those people, she medicated herself in improvised ways.
We have not heard the 911 call, but I don't think that there is a reliable information that she was really physically endangered in the house or being chased by someone with evil intentions shortly after she left the house. I do think that as some point, this exhausted, frazzled, disoriented young woman would realize that she needed a ride home and some predator in a car saw an attractive young woman in a low-cut top and tight jeans.