We live near a lot of hospitals and are planning on using this money to buy small multifamily properties and renting them medium term with traveling nurses. 

I believe this duration is ideal for attracting professionals on temporary assignments, traveling nurses, and individuals relocating or renovating their homes.

I was considering NC for a while but the wages for nurses are low.

There are many large hospitals in the area where it can be a great leverage to buy real estate and use it to target travel nurses.

My mother in law has had a condo in Cape Coral for over 20 years, wonderful area but the traffic has grown insane, all the time. 

But good to know the "...more time than anything else" part - so we'll need to restrict part-time nursing work to 14 hours/week. 

I live in my mother’s house, and we are considering possibly refinancing to purchase a multi-family property together (if that’s possible).Do you have any advice or insights on refinancing for this purpose?

My mother owns in another state but her home is paid for.

I started with my own funds as proof of concept, then started to do some joint venture deals and take other peoples money, only after I used my own and my mothers.

You could do long term or travel nurses since more HOA's have verbiage not allowing leaves under 30 days long.