Herself and her husband are still legally the owners of the property. She could try for a transfer of Equity which gives ownership from joint to sole name on the property, but this would require Mr's signature.
She could ask the lender for a quote for an interest only mortgage, but she would need to let them know over time of how she intends to pay off the remaining term of the mortgage, i.e through Endowment, or ISA's.
Other than that she should think about selling otherwise the lender will apply for a warrant (this usually when there are arrears of over 2 months otherwise the judge will through it out of court) for repossession.