On-again, off-again character traits

In the last post, we looked at part of Alyssa’s question. Here’s more: I gave my MC the ability to know if people are lying just by looking into their eyes, and if they are lying, then she can learn the truth. Also, she can understand the cries of infants. I realized that the eye-reading ability I gave her isn't in use much. I might use it three times in one page, then not mention it again for about 20+ pages. The infant-cry-ability isn't used at all.

I've also been thinking about expanding th...