Terms can vary widely in this category from annual interest rates, prepayment penalties, income calculation, DSCR ratio, maximum loan to value, minimum and maximum loan size, amortization period, and requirements to escrow taxes and insurance. 

Sell - Would prefer to avoid this to keep my low interest rate (3.3%) and avoid fees/taxes. 

She might not qualify for another loan, unknown it depends on if she can show it as positive rental income but with your plan it sounds like she won't have tax returns in the future to make this work. 

I invest in tax sales, mainly land.

Cost segregation studies can offer real estate investors massive tax benefits.

I consulted my cpa and he states that I will owe 100,000 in taxes leaving me with 600,000.

I am not going to pay 25*600 to file taxes for each entity :)

I have done short sales, tax lien purchases, sheriff auctions, wholesaling, / buying from as well as providing, PM about 500 doors growing to 1k in the next 17 months.

If the Florida property could cash flow or at least pay the mortgage taxes and insurance, utilities ect then they would just have a payment for their house by me.  

(plus higher property taxes due to the new assessed amount)2- I don't have cash for the rehab yet, so any advice on going about sourcing the 100k?