Also, he said that he needs to amend the document so that I can become an employee as soon as I roll over the 401k and Pension?

You may wish to confirm that the new 401k provider will handle the ongoing compliance support such as any required 5500 filing (e.g. 5500-ez for a one-participant plan with assets in excess of $250,000), any required tax reporting (e.g. 1099-r in the event of a distribution or in-plan Roth conversion), mandatory plan updates and amendments, etc.4.

I intend to start renting it out again sometime this summer.I claimed depreciation for 2018 (amended return) and will claim depreciation when filing my 2019 taxes.

I am fairly certain that zoning has been amended to not allow new separate structures for living purposes - must be an attached addition. 

My questions is, would you add her to the existing lease via an amendment of some sort or would you allow them to sublease and not mess with the current lease? 

After viewing we amended the contract to include the tenant vacate.

In Illinois, the statehouse passed SB1872 just last year, which amends the Illinois Real Estate License Act to require brokers licenses for wholesale transactions.

The gross per-month rental rate and any owner-offered discounts, incentives, concessions, or credits shall be separately listed and identified in the lease or rental agreement or any amendments to an existing lease or rental agreement.” 

Absent this, and with her broker's approval, she could use a real estate attorney to write contracts and associated amendments or addenda.Sorry to be a wet blanket with the broker and commission talk, but just trying to keep your sis and you out of trouble. 

Sometimes a tenant will want 3 years fixed but not as desirable to the landlord unless the landlord knows they are tearing the building down or eventually replacing a mom and pop tenant with a national one.You might want to take your existing lease and any amendments and have them reviewed by a local to the property  commercial real estate attorney familiar with that asset type (industrial, retail, etc.) and give an opinion.