"They received 1099 NEC in corp name for approx 48,000."

Are you describing that the corporation created a 1099-NEC for the shareholder? You cannot be a subcontractor to your own corporation that you also did the work for. Being a subcontractor would mean there is yet another "entity" under which they did this work, which is not true. Is there one 1099-NEC or two (one for each person)?

Or, was that issued to the corporation by a client?

And how does $48,000 related to all of the corporation's revenue? Or, again, is this the "drawn" amount, by one, the other, each, or both people? Detail really matter.

"or anyway compensation could be labeled as self employment income on the k-1 to be taxed as such?"

Absolutely not. A K-1 from their corporate entity will not supply SE income to them. Their labor is part of the costs for the corporation, reflected in payroll. Of all the ideas, this one is the least possible. And you already stated there was no compensation.

If they both worked for the business, I would bite the bullet and do a year-end payroll. That doesn't means using the $48,000 value. That means doing what applies, correctly.