traced a tenant for rent arrears - what can I do?

Tenancy Types and Management

Got a tenant evicted under S8, they changed the locks and eventually flitted after six months. I employed a debt collection agency who have traced them to their new address and made a face to face visit. The agency are still going to pursue them but the tenant has told them that she is now on income support and was not forthcoming as to where her husband was. As they have given me her new address (obvioulsy rented again) and that she has run up debts and creditors at my property is there anything I can do? Can I find out if she is truly on income support (the debt collection agency thought she was lying), Should I inform her new landlord if I can (and how would I find out where they are) of her history as she is more than likely to do it again, and thirdly should I inform / redirect her mail / give new address to creditors? Or should I just post back mail saying address unknown as I want to get some money back first? Should I try and take them back to court and if so what can I do? How do I get the attachment of earnings form that the solicitor said I could do?

I want to do as much as I can as soon as I can, I just need to know what is the best way to go about it.

Many thanks