A dated copy of the official program page and its questions and answers as read at each decision point, any official correspondence about her own case filed separately from general material, her payment records, and the written advice she relied on about the underlying category.
A figure without its date cannot be relied on later
Published government terms can change, and a number recalled from a conversation is unusable when someone later asks what was relied upon and when. Marielle should capture the official page each time it informs a step, with the date visible, so the file shows the terms as they stood when she acted rather than only as they stand now. Two categories of paper should never be mixed.
General program material describes the framework for everyone; correspondence about her application describes her case, and only the second is evidence of anything about her. Payment records should show the amount, the date, the payer and the recipient, because the direction of the payment is exactly the fact most often misdescribed afterwards. Where an intermediary made representations that influenced a decision, keep those in writing too.
If the representations do not match the official page, the official page governs and the discrepancy is worth resolving before proceeding.