I have a rental property that I have been doing long term leases with the same tenant. The first lease began in Oct 2014 for three years and I offered slightly lower rent for the long term lease. In early 2017 we began to talk about a purchase or a lease but due to work (and likely credit) she was not able to buy so she opted for a 2 year lease. During the three year lease she was a model tenant with very few complaints and always early rent payments. After the 2nd lease began (price only went up $20/month), so did the excuses and late payments. She works at the same large AF base as I do and I know her rank so I know this new job pays more so all things being the same she shouldn't have any problems with the rent. Obviously, things are not the same for her but while many of her payments are arriving late, they are arriving with late fees so that's not all bad.
Anyway, to my question... her lease is up in at the end of Sep 2019, so from a legal point of view how much time do I have to give her when I say that I am not renewing the her lease again because I want to sell the house? 6 months? 90 days? 30 days? I want to be done with the property since my "easy money" has become "hounding for money." Any help would be great.