This is because she did not find anyone who could fit her criteria, which made her decide to instead use the energy that is used by the Supreme Will to create a planet.
However, doing something like this is highly dangerous as the power required to create a planet is huge. Each planet has infinite possibilities, which is also the reason why there are not many planets in each sector.
For example, in the sector that they are living in, there are around 1000 planets created by the Supreme Will.
This may seem like a lot, but you have to know that each sector is huge. There are records of Great Emperor Realm cultivators who spent half their lifespans just to see how big each sector is.
But they were not able to touch the sector boundary, which is set up by those ancient cultivators. This is also why each planet requires its inhabitants to protect it with their lives.
