Signed and unconditional purchase documents, evidence that funds have left her control and entered the business, security documents showing what any borrowing is charged against, and a full trail from the original source of the money through every account it passed through.
Committed means the money can no longer come back
Adjudicators look for irreversibility, and cautious commercial drafting works against it. An agreement conditional on a visa being issued, a deposit refundable if the application fails, or funds sitting in a solicitor's trust awaiting an outcome all say the capital is not yet committed. Escrow can still be used, but the release conditions have to be structured with advice so that the money is genuinely at stake.
On the borrowing side, produce the loan agreement and the security instruments themselves, because what the debt is charged against decides whether it counts. Then assemble the source and path: the sale of the portable milling equipment, the timber revenue, the mortgage advance, the bank statements bridging each step, and the wire confirmations into the business account. Build that file while the records are still easy to obtain, not in response to a request for evidence.