All Cats Are Gray by Andre Norton description:
Under normal conditions a whole person has a decided advantage over a handicapped one. But out in deep space the normal may be reversed–for humans at any rate.
t sitting there listening to the talk–listening and remembering. She didn't open her own mouth often. But when she did spacers had learned to listen. And the lucky few who heard her rare spoken words–these will never forget Steena.
She drifted from port to port. Being an expert operator on the big calculators she found jobs wherever she cared to stay for a time. And she came to be something like the master-minded machines she tended–smooth, gray, without much personality of her own.
But it was Steena who told Bub Nelson about the Jovan moon-rites–and her warning saved Bub's life six months later. It was Steena who identified the piece of stone Keene Clark was passing around a table one night, rightly calling it unworked Slitite. That started a rush which made ten fortunes overnight for men who were down to their last jets. And, last of all, she cracked the case of the Empress of Mars.
All the boys who had profited by her queer store of knowledge and her photographic memory tried at one time or another to balance the scales. But she wouldn't take so much as a cup of Canal water at their expense, let alone the credits