Is this legal?

Location: Pennsylvania

I'm sorry if this is not the correct sub for this question. And I apologize for the length, in advance.

My wife and I have been married for 12 years. When we first met she was on SSI due to some medical issues that prevented her from working consistently. Obviously, when we got married I "made too much" for her to continue to be on SSI.

She's tried to get jobs throughout our marriage but ultimately, some sort of medical issue has eventually derailed all of them.

She looked into disability, but doesn't have enough work credits to qualify.

Here's where my question comes in...a few years ago I read where someone had gotten a divorce solely so their spouse could qualify for SSI. They continued to live together and all that, they just were no longer legally married. Is that legal?