I haven’t read everything. But be careful with using “I understand” as part of your validation. A lot of times, you might be listening and hearing, but understanding means more of bringing those feelings of hers into your own. And sometimes it isn’t possible to truly understand until you’ve lived through whatever she might be saying. For example, my fiancé has a very strained R with her dad - when she talks about how he disappointed her, I tell her “I understand how you must be feeling” but she tells me that I can’t possibly understand because I dont have those same experiences. It’s ok sometimes, but just be careful as it can be taken as invalidating.