I haven't gotten video of her going into my room, BUT I did get something else.  

I took the two things she "replaced" after stealing them years ago, and I placed them on the table near where she eats.  I've done this for several days. I remove them after she's done with dinner.  She can clearly see I am doing it on purpose, as when she eats breakfast, they are no longer there.  But each night at dinner, they reappear.  

If I confront her directly, she will deny it.  So instead, I leave them out so she can clearly see that I caught her.  And that I know it's her.  

And then today, she came knocking on my door to show me her books.  She said: 

"Hey Shay, I have something to show you.  I'll have to show you out here since you don't want me in your room." 

If you've been here, you know my mother ALWAYS tells on herself.  And that was what she was doing when she added that part in.  She NEVER says that out loud.  Plus, that would mean she would have to open my door and come in, something I've never allowed her to do (once I got a lock on my door).  It's been like five years, so why would she say that now?  Yup.  Because I've called her out on her coming into my room when I am not here.  

To me, that's her confession.  

Though, I will still put the items out in the kitchen until she actually addresses them.  Until then, I am locking her access to anything that's mine, per my therapist's instructions.  Ugh that feels like a lot of work, but I am down for it.  Otherwise it will drive me insane think she's sneaking into my room if I forget to lock it.  Or throwing my items away in my bathroom (like she did before).  I bet it's been going on for years, under the guise of "being docile" so I trust her.  

I don't need to confront her or argue with her about it.  I will just leave those items out until she has had enough and tells on herself.  She always does.