A dated copy of the official program page and FAQ, written identification of the official payment channel, the intermediary's authority and refund terms in writing, and confirmation of what immigration status the program grants and to whom.
If it is not in writing, it is not a term
Hypothetical example: The intermediary's verbal assurances are worth nothing if the program changes or the deposit disappears. Farida should assemble a short evidence file before any transfer. First, a saved copy of the official page and FAQ with the date, so she can show later what the terms were when she relied on them. Second, the published gift amount and processing fee, and confirmation from the official site of how and to whom those are paid. Third, a written statement from the intermediary of who it is, what authority it claims, what it charges, where the deposit is held and what is refunded if the program is suspended, if she is refused, or if she simply withdraws. Fourth, a note of what the official FAQ says about spouses and children, and about the status granted. If any of these cannot be obtained in writing, that gap should end the discussion until it is filled, not be papered over with urgency.
Hypothetical example: An architectural-salvage business owner receives a private invoice described as a Gold Card reservation. Before paying, she should retain the publicly issued terms, identify the stated government recipient, and compare the invoice with those directions. A payment record can prove that money moved, but it cannot prove that the recipient was authorized. The decision is simple: without written support from an official source for the channel and terms, do not treat a private invoice as program evidence.