There are additional benefits to the seller, too, as they are receiving interest on the payment and there are some tax benefits as well (I'm not an accountant!).  

If anyone could give me any additional info about the market.

What additional questions should be asking them?

I usually start with 75-80% leverage because that is what my bank will allow and once my leverage is down to around 50%property due to improvements or market appreciation and/or loan pay down, I use it as collateral or cash-out refi to buy additional properties or I sell it to buy something bigger because I am focused on growing my business by expanding my portfolio.

From what I understand, the annual gift tax excludes $18K per person (2025 limit), and anything above that either gets reported against her lifetime estate/gift exemption or requires some additional planning.I’m trying to figure out the most tax-efficient and practical strategy here.

In addition to that, we do monthly visits to our out of state properties & weekly visits to our in state properties.

It is a pass through entity though, and therefore does not impact taxes, other than additional filimg costs if you have an accountant do it. 

In addition to BiggerPockets, I’d recommend “The Note Buyer’s Handbook” by Henry Harrison, “Real Estate Note Investing” by Dave Van Horn, and “The Complete Guide to Buying and Selling Notes” by Steve Rachun — they’re solid go-to’s.

We're already a direct lender on the RTL side though, we're just adding additional products.  

In addition to private money, I'd explore hard money as an option for flipping.