I always believe that as adults we have the responsibility of looking out for and taking care of one another. That being said, have you addressed this with her directly in a non-combative, positive way. When I worked, I would boost morale and take care of the entire team, giving them the opportunity to correct their actions before I started down the accountability ladder. I noticed that given the opportunity, most people will shine. The others are less combative towards accountability measures and termination when they knew they blew their shot.
Everyone deserves the opportunity to improve, especially when the work of creating life is concerned. Doing it this way offers you the bonus of feeding your spirit and possibly building a good relationship with a co-worker.