The short answer
If your startup is most of what your family owns, a bad outcome is not just a career setback, it is a hit to their security. The money you would need for rent, school fees, a health emergency, and a runway to start again all sit inside one risky, illiquid asset. Startups fail often, and even good ones can go sideways for reasons outside your control. That is the real point of thinking about concentration: not doubt in your company, but protection for the people who depend on you. A small, boring cushion held outside the company (an emergency fund, some liquid savings) means a rough year does not force painful choices at home. Morgan Housel's writing on money is a good place to sit with why surviving matters more than upside, and Freefincal helps you plan the cushion. This is general education, not advice, so map it to your own situation.
A curated summary to orient you, not advice. The resources below are the real value.