She should also be making additional payments toward her student loan debt to you when she can afford it or when her income increases.

Each property has it's own LLC and bank account for which rents are deposited and expenses paid, but if one does not extract money from these business accounts, how can you keep increasing personal debt without increasing personal income?

I increase my marketing to reach more people. 

Investing $300k to split $75k is not a very good return - this is also assuming that nothing unexpected comes up causing the rehab costs to increase and the market holds level.

Still surprising to see the increase of inventory with all these developing houses but not seeing much job growth which kind of draws a blank.. 

I have to agree with Merritt - fresh water and moderate climate are going to be increasingly important.

If you lived in one unit and rented the rest, that may offset your rent and increase your return possibly, but I don't know if you would want to live in that area as well.  

I increased the weekly rent in 2017 and again in 2018 without any dip in demand.

WOW, thank you Andrew for your reply, it seems like if I purchase a brand new house, I will have to depend on the home price to increase and the chance is hard to predict.

Over time, as the mortgage interest declines, your net taxable income increases.