I’m making them a whole bunch of money regardless of what office time I put in so…

Don’t talk to her

Discuss your expectations for work with your new boss. Taking over unfinished work without any discussion on timeframe to complete is completely unacceptable. How are they going to handle that. Being both in a support role and being sent on expeditions by yourself undercut your ability to perform well in your role. Have them clarify how they handle coverage.