Funds received as a genuine, unconditional gift can be the applicant's own to invest, provided the gift is real and the lawful source is documented. What matters is that the investor now owns the money, has irrevocably committed it, and bears the risk of loss. A transfer that the donor can recall or direct does not meet that description.
State the gift's terms in writing, then live by them
Draft a gift instrument that names the parties, the amount, the date, and the absence of any repayment obligation or retained interest. Then check that the family behaves consistently with it: no side agreement, no donor signature on the business bank account, no expectation of profit share. The other elements still apply: treaty nationality, a substantial at-risk commitment in a real operating enterprise, non-marginality, and the investor's own ability to develop and direct it.
Two further elements deserve their own place beside the gift instrument. The capital must be irrevocably committed and at risk in the enterprise, so funds still recoverable at the investor's option, or held pending an outcome, have not yet met the requirement however clearly the gift is documented. And the enterprise cannot be marginal: it needs the present or future capacity to generate more than a minimal living for the investor and family, which is a question about the business rather than about where the money came from.
A perfectly evidenced gift funding a business that cannot support the household does not answer it. Hypothetical example: a prospective investor's family gift is documented meticulously, and the remaining work turns out to be the staffing plan for a residential renovation company, because the funding question was the one everybody had been worrying about and the capacity question was the one nobody had examined.