If you do then most certainly do a 1031 exchange into another winner of a property or even better do a cash out refi, provided that the debt load is sufficiently covered by the cash flow from the rental.

FHA 3-4 units has a self-sufficiency test which can be difficult to pass in higher priced markets where the rent from the other units needs to be greater than or equal to your total housing payment. 

So look around, interview other STR owners so that you have sufficient information.

Hi Rob,If you believe the HELOC will be sufficient for the purchase & rehab, it could make sense to use the HELOC given the interest rate is lower than a hard money. 

As long expectations are managed, either route should be sufficient. 

I have never tried that method but I would assume that the sheer amount of effort required to call enough people at random to generate a sufficient number of actual leads would be pretty astronomical.  

If I give her a move-out notice with 3-4 weeks in advance, would it be sufficient?

When you want to buy another property, your income must be sufficient to cover both mortgage payments (the new property mortgage + the higher balance on your cashout refi mortgage).

For example, just having a real estate license isn't sufficient to gain membership to a MLS, which I believe most are owned by commercial third parties...As for our local boards... 

We help investors to fund their deals, and making sure they have sufficient runway to qualify for multiple deals.