First, I presume that (i) you are self-employed; and (ii) you do not have any full-time w-2 employees (i.e. working 1000 hours or more per year) working for your self-employed business or otherwise working for you.

It'll spare her monthly budget in the short term, presuming she's a diligent saver and can pay those items later on.

Very low, a refinance would force you to give that up and because it is your primary residence and you presumably plan on living there for a long time it probably isn't the greatest idea to blow that up. 

You will collect some rent during those six months, presumably.

Three things you need to look at.A Power of Attorney statute in most states has a prohibition against "self-dealing" and a daughter selling her mother's house would be presumed to be self-dealing, regardless of having the purest motive in the world.  

Labor only I presume.

The other family member (presumably) lacks or lacked that ability.  

@Mark Pewitt I'm presuming this is a commercial loan (> 4 units)? 

Presumably it's better area, better renter, some chance for appreciation, etc.

also I presume I will need an architect?