8 yrs ago my dad was killed in a hit and run accident,mum proceeded with a claim to RAF via a lawyer who's policy was no claim no pay. My mum and dad was legally married till the day he was killed.They were never divorced.At the time of the accident my dad and mum was separated and my dad was living with by brother..

Did my mum have the right to proceed with a claim
After 5 years the attorneys who failed with the claim sends my mum a bill demanding her to pay.. they reason is because she did say that her husband was not living with her..
We are confused,are we being unfairely charged..

Please advise

Where? Were they LEGALLY separated or were they living apart?

It is unusual to be charged on a personal injury/death case - Attorneys are paid a percentage IF they win a case.