I think Patricia knows that the only people in San Alejo who will support her and keep quiet if something happens are Sophia and her grandchildren.Just by the thought and "hints" alone, I would bet that there will be something of a threesome with Sophia/Patricia/Dylan. The hints are very subtle but they're there.
Carl is wealthy with many connections and friends, Carl's father supposedly lived in San Alejo as well as Carl, and if Patricia had any romantic relationship it's certain Carl would find out.
So, for Patricia there is only one way: Sophia's family, where there is a blood relationship and discretion is guaranteed.