Apologies for not getting back to you sooner, I experienced some temporary connection issues and could not get back on the site until now. All appears to be resolved now so I can continue dealing with your query.
Whilst I understand her frustration and predicament, there is not always going to be an entitlement which will ensure he receives money. At this stage there is clearly a dispute which is ongoing and which she cannot help in resolving any sooner. There is not much she can do in relation to that, apart from assist HMRC with their enquiries or hope that the employer comes forward and provides the relevant information.
In such circumstances people will often have to resort to getting help from family and friends, relying on loans or credit cards or checking if they are entitled to other benefits from the government.
She can go through the Benefits Calculator to see if she would be entitled to anything else in the circumstances, but sadly these are her only options at this stage, even if she has not done anything wrong.
I'm sorry if this is not necessarily the answer you were hoping for, however I do have a duty to be honest and explain the law as it actually stands. This does mean delivering bad news from time to time. I hope you understand and would be happy to provide any further clarification if needed. If you are still satisfied with the level of service you have received I would be grateful if you could please take a second to leave a positive rating by selecting 3, 4 or 5 starts at the top of the page. Thank you