Lauren is not currently an active agent, as the MindMerge technology proved less effective on her every time it was used. She took Robbie under her wing and by return, Robbie (and to a less extent, other members of Team Gamma) covered for her when the MindMerges started to fail mid-mission, sometimes endangering them all.
We first meet Lauren on a mission that pits her and Robbie against a Cybok. Her MindMerge broke down completely and she is currently in ReHab. When she recovers, Professor Phillips will have to decide whether to give her one more chance as a field agent or ‘retire’ her.
Robbie feels guilty about this because he knew she was having problems, but didn’t say anything, thinking he was protecting her.