If Greta decides to act for Monty on this transaction what offences could she potentially commit? Can she protect herself? in the scenario

Greta Murray is a solicitor, at a law firm called Merchant Legal, based in Manchester. This morning, a brand new client, Monty Munro, came to meet Greta. Monty wants to instruct Greta to act on his behalf in relation to a building he wants to buy. Monty is a businessman. He explained to Greta that he wants to buy a building on the outskirts of Norwich, which is for sale at a very low price. Monty is sure many other people will want to buy it, so he needs a solicitor to act very quickly to get the deal done as soon possible. In addition, Monty wants you to deal with the purchase as soon as possible, as he is going away soon, for a long holiday to Brazil, South America. Monty says he already has the money for the purchase, in cash. He wants Greta to put all the cash into Merchant Legal's bank account, so the money is available when needed. Monty said he has been given the cash by his brother Zane, who is currently serving a long prison sentence. Monty tells Greta that his brother had just been unlucky to end up in prison as he had become inadvertently mixed up with some local criminals and it was all a big misunderstanding. Monty thinks this could be a good opportunity to develop a new client for the law firm but wonders what her legal and professional responsibilities are?