You mentioned it was 3% interest only however the math calculates to a payment of around $3950 a month if it is amortized at 3% and 30 years starting with a unpaid principal balance of $937,000.  

Areas with a healthy balance of supply and demand will have more motivated sellers and active buyers.Consider Price Points: Target markets where homes are priced in the sweet spot for investors, often between $100k and $300k.

and, if you're borrowing a 25% down payment with a HELOC at 9-13% interest, and using a loan at 6-8% for the balance... that is very, very expensive. 

Overall a decent balance.  

The plan is to give her 10% downpayment and the balance is seller financing.

The deferred origination fee is paid to the lender when the loan balance is paid off, so the borrower comes with in with less money down at the time of closing, but is on the hook for the fee once they successfully pay off the loan. 

This will help to minimize legal liability and any concerns that could arise regarding employee theft (We plan to retroactively count the RV rooftops present at noon each recorded day (every 30 days), and compare it to the park management software/bank statements as a system of checks and balances.

With a months' supply of inventory now at 4.4, up by 37.5%, we’re seeing a more balanced market.

My thought would be househack with minimum cash contribution, force some equity, then do a rate/term refinance roll in costs and get refunded your escrow balance and another $2k at closing. 

Increase in family size:A Borrower may be eligible for another house with an FHA-insured Mortgage if the Borrower provides satisfactory evidence that: • the Borrower has had an increase in legal dependents and the Property now fails to meet family needs; and • the Loan-to-Value (LTV) ratio on the current Principal Residence is equal to or less than 75% or is paid down to that amount, based on the outstanding Mortgage balance and a current residential appraisal.