Her master and the current patriarch of the sect was talented enough to survive advancing to the fifth mortal coil with a weak body, but she isn't that talented.
She only managed to create a ninth transformation golden coil, so she will be missing one more transformation to the peak of the fourth mortal coil.
Not only that, her body is weak and might give out early when she is in the middle of advancing. Plus her sect lacks the resources to ensure her success.
These conditions are the same as the ones that the two seniors before her had. Those seniors failed to advance, so she knew just how bad her chances of success are.
This is why she reached out to the Red and Blue Fire sect and offered to betray her sect in exchange for their help to advance to the fifth mortal.
The Red and Blue Fire sect didn't reach out to her. In fact, the Red and Blue Fire sect doesn't consider the Purple Flower sect a threat at all. After all, they have the advantage of number and quality.
