I agree with Eddie that there is certainly a side to that line which suggests that Leia succumbed to fear in the same way that Anakin did. It was one of the first ideas I had when hearing that line.

The problem some seem to have with it is that Ben ends up dying anyways. I think that’s kinda the point. Leia is at a crossroads when she senses Rey and Ben fighting to the death: use her Jedi powers to reach out to her son (and risk his death, anyways), or let one of them kill the other.

Of course, Leia let go of her fear because she just wanted to let her son know that she has forgiven him. As a result, he is turned back to the light, and they are able to be with each other in the Force. So even though he dies, Leia would definitely see that as a better alternative than letting him die as a dark sider (wherein he most certainly wouldn’t be allowed to become a Force ghost).