Haha my thoughts exactly - so many red flags!
They moved in together after knowing each other for only 6 months too 
Do she sue him?
Hope she does
It’s too difficult to prove it. Like she said, the credit companies wouldn’t listen as it was all done online with all her details, none of this links back to him. It would just be her word against his. She would need hard evidence, which is pretty much impossible.
This happened to my mum when I was a teenager she told me many years later. Her then husband got her to take out credit cards and he spent on it. As @xstex states, its too difficult to prove. In the end, Yorkshire Bank took pity on her and gave her about a £10,000 loan to cover the cards, which she took about 10 years to pay off due to her low income.
A mentally abusive relationship can control people and make them do silly, if not outlandish, things.
Just a note to everyone. On digital signature, it is up to the person who sign it to prove you DIDNT do it while wet ink on hard copy it’s the bank to prove it IS YOU
This is was advised to me by our solicitor when I worked in the contract department.
That’s why it’s so hard to prove. You have to show the time a digital signature was produced you and no where near the hardware that produced it through.
Can she not find out what the money was spent on and get the delivery address from the online shops and prove that she doesn’t live at that address?