After the initial application and processing fee, USCIS sends instructions to complete Form I-140G with supporting documents through the portal, and USCIS or the State Department may request additional information. The public FAQ does not publish a fixed degree, licence or source-of-funds document list, so the current portal instructions govern and the gift should be sent only when requested after vetting.
Prepare the immigrant case first, the payment second
Hypothetical example: the dentist assumes the application is mostly a payment form. The official public process is more specific: submit the online application and non-refundable processing fee, wait for USCIS instructions, complete Form I-140G with supporting documents through the portal, undergo vetting, and send the gift only after successful vetting when official payment instructions arrive.
The public FAQ does not publish a fixed list requiring a dental degree, provincial licence, practice history or source-of-funds package, so those items should not be presented as official Gold Card requirements. She should follow the current portal requests, provide any additional information USCIS or the State Department asks for, and re-verify the official terms before moving money.