Oh dear. a contract will include all agreements made between the parties both verbal and written but and I'm sure you know what I'm about to say, verbal agreements are of low value because it is open to one of the parties to disputes or deny claims of what was agreed when the other party relies on verbal agreements alone. the obvious benefit of writing something down is that it is prima facie evidence of what was agreed.
On the face of the evidence, your colleague has quite simply agreed to buy a car as seen and paid a deposit as part of the purchase price. That agreement is particularly unhelpful both in relation to the deposit which she now would like back was also, where she to proceed with the purchase, because she has signed to say tthat she has bought the car as is warts and all as may be which would potentially give her little redress if she later were to discover a problem. Also of course if certain repairs were agreed as conditions of the sale, it would be open to the other party to deny ever having made such an agreement.
In the circumstances, it seems to me the best approach for her to consider would be for her to email or text of the individual to whom she paid a deposit and refer to their discussionn with regards ***** ***** works that were to be carried out to the car and ask if those works have yet been completed and to do so in a casual manner. The reason for this is that his reply, providing she sets out the works that were discussed to be carried out by him, will potentially be evidence of the agreement that was made - i.e. if he says they have not been completed yet. of course, he may reply stating categorically that he never agreed to such works which would be problematic the above reasons.
If he does accept that the works were agreed to be carried out and has not done them, then she could send a second message stating that as the works have not been carried out, the conditions of purchase have not been fulfilled and accordingly, she is repudiating the contract and requires the return of her deposit because he is in breach of condition.
If he has carried out the works that have been agreed and she has simply changed her mind, then she would need to agree with the individual to cancel the agreement. He may refuse or agree is subject to retaining wall or a proportion of the deposit that has been paid