To add to what I mentioned previously, and the comments above, there are several other approaches to this, aside from your sister becoming a real estate professional, and meet it's requirements, or having you employ her, and as a salaried employee, requires you to carry unemployment insurance, workman's comp, filing state, federal with holding tax etc. 

Now the tenant states that her employer cut back her hours for who knows how long and she's trying to get the funds together ASAP.By the way, I fully understand that I should have served the Pay or Quit notice right after the tenant went late the first month, but lesson learned and I'm just trying to move forward at this point.

Rather, you need to work at least ~2,000 hours in employment where you have your Solo401K, which in this case I believe would be on your real estate investing.

.- Can employment be used an exception for the non-qualified use period?

My employer only charges $75 and funds in 2-3 business days. 

Did you establish a tenant file for him which includes a copy of his driver's license (or other photo ID) and a copy of his personal check (that will show his bank account information) and information about his employment situation (for possible garnishment)?

Uber is not a job it is a independent contractor with zero job security, no guaranteed income and generally speaking engaged, as a form of employment, by individuals that do not conform to the norms of society...ie regular employment.

In AIR leases, the most common form leases used nationwide, that provision is at 150% of base rent.If your lease does have a holder over penalty provision you could use that as leverage to enforce prompt payment of the "base" rent.Otherwise I agree with the mention by another that if he's not willing to renew the lease and pay his rent on time then you'll have not choice but to employ the service of a towing service to monitor your parking lot.FYI, most commercial leases, unlike residential leases, have a grace period of ten days.

Just as employers give gifts to their employees to show appreciation for their hard work, I wanted to express my gratitude to my tenants for being awesome.

Called and left messages at his place of employment but never get a return call.