What to do with the employee that says they can do it all but can't.?

• employee relationship management
• drug abuse info

We have an employee that is good at what she does but tends to take on a lot more than she can actually do. At this point, her taking too much on has resulted in customers not getting calls back, orders not being processed, sales leads that go unanswered, info not being sent etc. The CEO approached the situation by asking her to hire another person to support her but she refused and again said "I can handle it all".


It has been a few months now and nothing has changed. Still many things not getting done. I think she is sensitive about that subject of bringing support on but I am not sure why she will not. We have clearly communicated that this person would be below her position and not be taking her position. What is the best way to handle this going forward so it does not limit our growth.

What to do with the employee that says they can do it all but can't.?