If they continue to smoke in the apartment, you have grounds to file for eviction due to them breaking the terms of the lease.

We have been contemplating our strategy to start our business by having my sister buy her first home locally here in Connecticut, a duplex as her primary residence and live in one unit with our mother, while renting out the other unit to a resident, and be able to also rent out her single-family house as a short term/midterm rental to traveling nursers/working professionals on furnish finder.

You might also be a good candidate for a small boutique hotel, an operator looking to retire will often entertain seller financing on fair terms and you could likely qualify for a SBA loan to help with your vision. 

Is there a standard letter that I need to send tenants a month before the end of their lease to remind them to move out by the end of the term?

It might be easier to treat it as a full scenario with Purchase price, Down payment, Term, Prorgam, occupany, number of units/rents per door, Taxes/Insurance (Any flood, HOA) etc. 

. - These are the two channels where these companies will seek out listings for their housing requests.Longer term you should be networking with businesses in the area that are known for having housing needs for their employees.

Over $5,000 takes you into district court, which can be significantly more costly in terms of time and expenses. 

It does take a little playing around with the numbers and knowing what you are comfortable with in terms of risk.

Hey @Noah Yashinsky, South Florida is more of an appreciating market rather than a cash flow market for long-term rentals.

I realize I'll need to look at zoning, put together a site plan, etc. to know exactly what's possible in terms of how many units can fit on the site.