That’s a good question. In such a situation, there is probably not a lot you can do except tell her she absolutely must/should hire a CTO.
Additionally, make sure you have an “insurance” in the form of a paper trail: Whenever she says to come up with feature XYZ, provide an estimate how long it takes in written form. Later on she cannot blame you guys for not having told her, you actually have proof. If you want, you could also do that as part of a an architecture decision document. That’s unusual as the document is not meant for that, but together with the architecture decisions you have a captured each and every rationale why you think building XYZ actually takes so and so long. When I manage projects with a moderate to high degree of complexity I typically add 20% - 40% overhead time to my high-level estimates for the “unknown unknowns”. I know that stakeholders typically don’t like that, but we all know that projects follow the 80/20 principle.
The meaningless, over-the-top violence spread in so many computer games is a real turn off to me.