They’re so drift compatible they Ghost almost constantly—for the record, “ghosting” is basically drifting even after the neural handshake. So Fitz and Jemma essentially share a brain, and their jaeger has an equally misleading name; Unicorn Gemini, (Scotland’s national animal is the unicorn and by god I’ll never let that go.) So people assume they’re twins.
They were actually scientists working on the robots and studying the Kaiju since they couldn’t pass the field requirements of being jaeger pilots, but by the second year of the program Nick’s so desperate he lets them pilot and it’s alternately the worst and best decision he’s ever made. They’re fantastic pilots but even MORE inseparable now. They talk in unison and finish each other’s sentences and it’s really just unsettling to everyone else.
Jemma also is the one who makes deals with the local Kaiju dealer, Raina.
Also; Fitz has definitely climbed out of the jaeger to perform emergency repairs and he thinks this’ll stop the jaeger from moving but Jemma’s ghosting is so strong they manage to get the jaeger out of the kaiju’s way while Fitz makes the repairs.