BM - Yes - just what I thought!
If I've got this right, she put no money into the property herself, but is a joint owner & on the mortgage. There is also a joint second charge (for the equity he took out). She wants to get off the mortgage & second charge, & wants some money from the joint owner to do so. If I'm correct, & she has put nothing into the property why does she want money to get out?
She can only get off the mortgage & second charge if the lenders agree. That may be difficult to achieve, as the boss's business went bust & he may well not have enough income to support the mortgage & charge himself.
There is a Mortgage Code of Practice (MCOB) which should be followed by mortgage lenders. I don't know the content. She needs to get this checked in case there is anything there giving the lender responsibility for ensuring that someone in her position is properly advised before taking on the responsibility of a mortgage. If this is part of the code & the lender did not carry out their responsibility in accordance with it, she may be able to succeed in an argument that she has no liability for the mortgage. This is a long shot, but she could approach local CAB to see if they can help.