If they are married but living apart and she needs assistance from the government, she'll be forced to file for a divorce.
The Church does not, and never has, condoned long-term separation. A separation would be for 2-4 weeks. Long term separation is immoral.
Secondly, you're assuming the man wouldn't support his wife during the separation. Again, if the Church approved of it, he would have to go along. If he didn't, then that's a larger issue which I don't know enough about to answer. I'm sure she can get some friends to help for 2-4 weeks and figure out a housing situation.
she'll be forced to file for a divorce. This is not denying that she is still married, but acknowledging that she's in need of financial assistance and isn't going to get it from her husband. This does not mean she's abandoned the marriage and does not mean she's certainly at fault.
No one is FORCED to file for divorce (see how the liberal mindset has already crept into your psyche?). The only EXTREME case would be to protect your privacy or finances from an abusive/violent or gambling/drug problem. But this is extreme.
All of you women are jumping to conclusions and 'worst case' scenarios, when in fact, most divorces are for petty, frivolous and "emotional" reasons. Stop watching lifetime movies.