Perhaps a code review on her first few commits would be useful? Like, take an hour and sit in a conference room and have her walk through the changes and explai

Perhaps a code review on her first few commits would be useful? Like, take an hour and sit in a conference room and have her walk through the changes and explain each one. You probably can't eliminate GPT all together, people will always find a way, but asking them to explain their thought process might give insight into how much they're leaning on it.