There are rumors Rochester might go for governor instead. Though they might only be if Carper stays.
Going for gov would give LBR the opportunity to write history as first black female gov. There has never been one and is unlikely until the 2024 elections. Of course, unless some lt. gov. like Juliana Stratton has to fill a vacancy before. Though Rochester would still be the first AA woman to win an election for a state's top job.
Being Governor these days seems like a more fulfilling job than being in the Senate especially governing a state where your party has a trifecta like DE. LBR has some executive experience previously being a CEO of a non profit and a state cabinet secretary so she may be more drawn to running for Governor.
Somewhat unrelated to Delaware, though I always felt being governor was a preferrable job than senator. You can actually implement policies and more effectively use the bully pulpit. Being governor is also a better "training ground" in general than the senate, because a governor has to get things running and at some point has to function as a crisis manager.