look at this
I am guessing that He Is Honor the almighty
I think that Cultivation influences some of the bonding. She wouldn't be able to control the spren that become non sentient because they wouldn't remember a thing. However, she might be able to influence who they are drawn to. Syl seems to have no recollection of the Nightwatcher or Cultivation. I think that the spren that do retain memories are loyal to the Nightwatcher like a child to the mother. They would want to follow her wishes. The ring noticed that Lift had her blessing and so they decided to send Wyndle to her. It is possible that this is a situation a lot like the Kandra. Many hadn't ever seen the first generation. The ring might be just as much at a loss about what their Mother wants.
Here is another thought, though, we may already know this. Maybe the only spren that can bond are the mixture of both.