Split the money before it is spent. Capital promised to the enterprise cannot also be the household's reserve, and an enterprise expected to support the family alone raises the marginality question. Eligible spouses and unmarried children under 21 may accompany the investor as dependents; a qualifying E spouse is generally employment-authorized incident to status, so household income planning should account for that separately.
Ring-fence the household reserve
Decide, in writing, how many months of rent, schooling, insurance and food sit outside the business account and stay there. Then check the spouse's own position: work authorization for a qualifying E spouse flows from valid status, and the E-2S notation or I-94 record is what an employer will want to see. Children do not gain permission to work through dependent status.
Neither the investor nor the family gains permanent residence from this category. Add one further protection to that ring-fenced reserve: decide in advance what would justify touching it, and who has to agree. A reserve that exists only as an intention is drawn down gradually, in defensible increments, each of which seems reasonable at the time.
Naming the circumstances in writing — and requiring both adults in the household to agree — is what makes it a reserve rather than a preference. Hypothetical example: a household funding a packaging supplies distribution business writes down that the reserve may be used only for medical costs or a documented failure of the business, and when an equipment order runs over in month four the overrun is funded by deferring a hire, which is both a better commercial decision and a more defensible one.