Dr's, Nurses, Electricians, heavy equipment operators etc etc.. 

She rented out the second bedroom to a traveling nurse and found that the rental income not only covered half her mortgage but also let her save for her next property.

Nursing is one of the best professions in the world NOT to have to transition out of.

As Kevin points out, traveling nurses make good money, and their employer pays for their housing.

However, there are types of tenants (similar to travel nurses in the US) which can be tapped into providing a consistent level of higher rents.

For instance, there is currently a nursing shortage across the US, and traveling nurses help to alleviate it.

@Marco Teixeira I'm looking into it as well, the main two issues I'm trying to solve are that not only you have to find the property but be conscious about to which city hall that area belongs, that makes a huge difference in time frames if you want to license it as senior living, the other thing is scale, it's more management intensive (staff 24/7, doctor visits, nurses, food, etc...) therefore if you don't have enough beds it might not make sense, you'll end up having to charge too much per person for you just to break even, that being said there is definitely a HUGE demand for it.

Another option if you are looking to rent rooms and there are hospitals in your area is to market to travelling nurses, using a website like https://www.furnishedfinder.com/  These are shorter term leases, usually about 3 months, and you are renting to professionals who are in an area for work.

I would like to convert the garage into a one bedroom and rent either to another long term tenant or mid term (30 day min for professors or traveling nurses). 

You will be within close proximity to the University and approximately 5 minutes driving distance from the main city area, which also includes the hospital (could be good maybe for a medium term rental if close enough for travel nurses).