It SHOULD be shared, yes. But in her head, I think sharing she believed sharing would have done more damage than good.
The realities of the damage of whatever she suffered is probably unbearable to her, which is why she tried to kill herself twice.
When someone has a life like that, they hope to start over and leave the past WAY behind them. Sadly, they aren't even aware of the damage that will cause themselves and anyone else they love.
I pray your ex finds it in her to begin on a path of healing for herself and for the children.