If you transfer it into an LLC after securing the HELOC, your lender could invoke the due-on-sale clause, meaning they could demand full repayment of the loan immediately.

Are you going full tenant-style background checks or using something lighter for short-term travelers?

Are you full time in real estate?

Does it need repairs or a full replacement?

Time they have been around is important.

Unless you still want to buy the property, the seller is in breech for not closing because you are full ready to close but they haven't or refused to sign anything.In NC if the seller breaches, the buyer can sue for specific performance.

You should have posted a 3 day notice a few days after the first time they were late AND every time after that.

Something like: "Know that if you don't pay your full rent by the 01, I will file for eviction".Or should I just wait and if she passes the 01th, file for eviction?

I've hosted 12 units by myself in the Tampa Florida area, but it was my full time job.  

I've been in the BP community for over 10 years, I've been featured on the podcast 6 different times, RTR has over 270 5 star reviews, and yes, I've been a long time sponsor of BP as well.