experienced childhood trauma, and has moved on
With kindness, OP hasn't been able to move on, she is stuck in a limbo stage on not dealing with her past issues but successfully ignoring them.
I've had to compartmentalise aspects of my life and childhood due to trauma.
Like OP, my peace is only achieved by never seeing, never speaking about, thinking about, or acknowledging what has happened in the past, because some things you just can't move on from so you have to almost pretend they didn't happen.. it is really not healthy IMO, but if it works it works.
I had a similar thing happen to OP, I was forced to make a choice, carry on ignoring and pretending, or confront and hope to get some sort of closure, I decided to confront and it was the best thing I ever did to be fair, nothing changed in any way, apart from the way I felt from then on, I felt I could move on and not actually care anymore, rather than pretend not to care.
These people aren't the ones responsible for OPs childhood trauma, they are just a reminder of it, so I do think it would have been better for OP to have shut down the original contact via email, or failing that to shutdown the visits by leaving a note or handing over a note when they came back to that effect, I think ignoring problems that can easily come and find you means you are never going to be free of them, so if you (understandably) don't want to confront, then the best you can do is make your position abundantly clear and hope they have it in themselves to respect your wishes.
Not specifying your wishes, really will leave things open to interpretation and leave you open for future contact attempts.