I'm not sure how much this matters in terms of staying longer in my condo vs buying a new primary, but I did just a few months ago upgrade my HVAC ($12k) and am doing other value-add to it in the meantime. 

The big question is this - is this 'marginal' area going to a) stay where it is? 

I'd politely tell her that if she isn't happy there (which seems to be the case) you will give her the one time option of breaking her lease without penalty if she moves out within 30 days (eg Nov 15) and that she has until Oct 15 to decide if she will be staying or not.I agree with Kevin about phoning and then follow up with a brief summary of what you talked about via text.A lot of people here own a few places (not dozens) and most of us also have full time day jobs, so balance the two. 

I enjoyed reading your post and the sense of newness and freshness of the start of your journey.

Buy modern fixtures to make the place as fresh as possible without spending too much money.

Stay in your lane.   

(Existing tenants intend to stay on.)

., you want to stay away from those. 

From now to April has been a slower season for us in that our properties stay vacant for longer this time of the year.

Did the tenant stay for the stated period?