I ask because as mentioned above if you have an investment that is  going to return 10%+ then does it matter what the rate is in the long run? 

When you draw from the equity, you are "borrowing" it from the bank and have to pay interest.If you borrow against the equity at 7% interest and then loan it out at 15% interest, you are earning a positive 8%. 

I would then work to renovate the bad unit as quickly as possible.  

If you have a competitive advantage that you can bring to your co-hosting/managing, then I would recommend looking for owners with properties that mesh well with your target resident.For example, if you are an active duty military servicemember with unique insight into what a servicemember is looking for, lean into that.

Find someone you know, like, and trust, then partner with them on a deal.This doesn't have to be an existing investor.

If you are trying to continue holding the other two properties then you should pull out some equity in the form or a cash out refinance on one or both or use a portfolio loan as @Jimmy Murray suggested.

Then you’re going to ask her to give you a 3 year 0% loan?

As your portfolio starts to increase, you can start creating single-member LLCs where the property is located, and then you can put all these LLCs in a trust.

You are VERY easily able to open accounts remotely by just uploading your EIN doc and then once your biz account is open you can open additional accounts for things like holding your security deposits, reserves, etc.

You have to borrow your equity and then make payments on it.