I'm looking to leave to start my own business. I'm managing a team of 9 developers and our president is not very tech fluent to say the least. Also, our president is about to let go of an underperforming member of the team, assuming I'll be there in the future. However, I will likely leave in the next month or two and I don't want her to get fired if there's no other replacement first (and without him knowing the real situation). She's currently on vacation and when she's back in two weeks, she will be let go of. Should I inform the president of the company that I'm likely leaving? Yes, the person about to get let go was underperforming but she does have a lot of information and knowledge that I have.
I would love to do right for both myself and the company, but I definitely don't want to hurt myself to help the company.
Edit: I know that similar questions have been asked before, but the difference here is someone is about to get fired while I wind down from here and I don't think she gets fired if the president knows I'm leaving.