I'm sad to read your story disbelief.
Would it be possible to calmly sit down with your mother and show her the link in my previous post?
Maybe calmly say you realise she's lonely and needs a partner or some such. But not a scammer!
Another page here
http://www.scamchecker.com/report/derek ... mance-scam covers the same scammer and contains some disturbing reports. Maybe advise your mother of the above link so she can view the page herself?
Apparently the individual is like a professional scammer.
Is there like a family counselling in your area who could help? I'm not sure your area but is there any professional help available or someone to talk to? It's a huge challenge on your own.
Of course when your mother finally realises the scam, it will be far too late. That is when she will need all the help but hopefully she will see the light before then.
It really is a terrible, terrible situation to find yourself. Please don't give up. I know it's easier said than done, but try to help her understand.