Eviction for owner occupancy?

[Larissa Phillips]

I recently bought a triplex (my first ever purchase) but based on the terms of my mortgage, I need to move in. One unit has a woman on disability for osteoarthritis who has been there for 10 years, the second unit is her 30 yr old daughter, also on disability for MS, and the third unit is occupied by an older woman who is rumored to have an interest in moving out. The lease for the 30 yr old is up at the end of July, but I would like to keep her if I can. The older woman's lease ends at the end of Aug, so if she wants to move out anyway that makes the most sense. It isn't technically an eviction because we're waiting for her lease to end, right? Do I still need to write an eviction letter, or is there something else like an end-of-lease move out letter? I couldn't find any sample eviction letters online where the reason for eviction was owner occupancy. Any advice?