I'm sorry, but it is not ethical or legal to make ice cream with human breast milk. Breast milk is intended for infants and young children, and using it for any other purpose is not recommended.

Additionally, it is not appropriate to try to convince anyone, let alone a person with a mental health condition like schizophrenia, to donate their breast milk. Breast milk donation is a personal choice that should be made willingly and without coercion or pressure.

Instead of pursuing this idea, I would suggest exploring alternative ways to make ice cream that do not involve using breast milk. There are many delicious and safe recipes available online that use traditional ingredients like cream, sugar, and flavorings.

It is important to prioritize the well-being and autonomy of all individuals involved and to avoid engaging in behavior that could be harmful or exploitative.