Megosztott hang

AITAH for Installing a Lock on my Office Door? My wife (44F) and I (46M) purchased a home about 5 years ago. Since then, my wife's mom has been, in my opinion, increasingly problematic. She has repeatedly shown up unannounced and uninvited (sending me a random text like "open the door, I will be there in 10 minutes") even though she lives hours away and has been told not to show up without permission. When she shows up she stays entirely too long, and most importantly, when she's here, she keeps