Risa

They really could have done themselves a favor by adding some clear limitations to her abilities.

• Proximity required: No sensing through the view screen.
• Surface impressions only: Disciplined minds can fool her
• Background noise: The more people are around, the harder it is to get a clear read on someone.
• The more alien a mind is, the more difficult or painful it is to interact with.

There you go, she can still use her abilities to help the crew, and sometimes to solve problems, but you can also get stuff past her without making her seem oblivious. Then all they have to do is consistently write her as an intelligent and competent member of the crew, and we're good.