this may sound a bit strange but when I felt like crying on the inside and wasn't crying on the outside I would put on a sad movie like "Beaches" , watching sad drama movies would release the tears for both my inside child and I.

its a weird situation with Dissociation that I learned about in a psych class. you are integrating so I have no problem sharing this with you....

theres this natural brain activity thing that goes on. everyone has the normal brain activity called "flight or fight response" dissociation is part of the flight or fight response. its not something a person can control just the way the brains electrical impulses naturally does things. it knows based on what is stored in your brain what goes where.

the more you know and learn the faster this integration works. Think of it like that broken vase in the corner. you look at it nothing gets fixed you google you go to ceramics DIY and other classes that teach you how to repair things, you learn enough that one day you pick up the vase and repair it.

integration is where the brain stops sending whole things through the flight response to the unconsciousness (dissociated storage tanks) when the dissociative side doesn't have the answer it means the answer did not get sent through. the brain kept that trigger on your side but sent the response to her side. you can see this in your post where you state in your words "I think we read something that was triggering, but she doesn't know. "

you have healed enough to face the trigger but not the response to the trigger (the crying)

By watching something sad that releases the sadness in me to that the alter inside me no longer feels the sadness. why because Im dealing with sadness rather than my brains flight or fight sending sadness to the dissociative side. watching something sad and crying about it also gives my brain another pathway so that its no longer sending sad things through the flight route (dissociation)

That's how I solved this situation. by teaching myself how to cry on the outside, that its ok to cry. by doing it in a way that I can control (a movie where I can pause it, rewind, fast forwards, watch it again,...)

my point is since you have the information of what the trigger was (reading something) and she has the response to it (needing to cry) maybe there is a way that you can reconnect the two things reading something and crying while at the same time you are in control of how you are reading something, pick a book or movie that has something sad in it and go through it as fast or slow as you need to in order to not have the response (need to cry) go through your brains flight response. use your tools you learned in therapy to keep you grounded while doing this.

that's what worked for me, maybe it will help you.