Oh my goodness, really? A zillion things...

One was talking about a specific side effect of being abused
Another was sharing my needy feelings for a mother-figure with her
Another was telling her I was angry at her
Sharing about certain traumas in general was hard: I find in general, writing is so helpful to starting those disclosures.

How did I do it? Tentatively, lol.

In the first case, I asked her to help me disclose by asking me some questions.

Indeed, I think her asking very gentle probing questions, rarely but at the right moments, has been very helpful. I don't usually like being questioned at all, and will talk on my own, or not, as I feel best, but in those cases, they helped.