It is very common for what Harper is feeling. Humans for the most part do not enjoy change and it can be difficult to acclimate to change. This with added on stress could make anyone feel defeated.
The first tip I would suggest for anyone being in this situation is to voice their concerns as well as needs that could help on finding a solution. It looks like Harper has tried to express her concerns to her new boss. But it seemed that her needs weren’t not met.
The next step would be reporting the issue to HR. Here HR can coordinate with David on an action plan. The first step is seeing if filling Jose’s positions would be in the companies best interest. If there is an ability to fill his position promoting Harper will be a huge advantage for the company. She has been with the company for about 4 years and worked under her previous boss very closely. If not hiring someone into Jose’s position is not feasible then steps to showing acknowledgment the good work Harper has been doing needs to begin. The company can also use other employees to delegate task to so Harper doesn’t feel all the pressure themselves.
Losing Harper would cost the company more money because they will need to find another person to fill her position and train them which take a lot of time and energy.