I see your point,
@Zoogal , but there is more to it than age. Personality, relationship boundaries, and other variables, such as her technical abilities; if she couldn't get to Word without opening a minimized doc and starting a new doc, then it's less offensive. Legally, it was in plain view.
I have known "normal" 26 year olds who need their mom to go with them to the Dr. and Dentist, and hold her hand, and she will call their mom every day, etc. Turns out that young woman was going through acceptance of herself as a lesbian, when she hadn't had that level of self-awareness in the past. She had always been "different" and maybe curious, but she didn't identify as LGBT until 27. Not uncommon. Some of her functioning was delayed because she had unfinished psychological work underway (it's called "benign regression" when people act immature whilst moving through a major psychic growth spurt).
People have delays in their functioning that is not all "character" based or "behavior" based. Also, was it okay to open other files in the past for specific reasons, such as to use them as a template or a guide, and this was not a huge invasion of privacy to the daughter? It depends of the family culture.
I won't assume that this was offensive in any specific way, or a crossed line that should have been known until this Mom says it is, just based on age; and maybe she did, and I missed that element. I only see that she didn't want the whole story out for this audience yet, and she wanted a controlled release, later, maybe. The older I get, the more I am aware of what I don't know, and should not assume, based on one fact. People are more nuanced than I thought. I don't get offended on behalf of people like I used to do until they tell me that they are offended.
Sometimes it's open and shut like that, but sometimes, there is a reason for the behavior or it highlights something.
In this case, I look at it from also the 28 year old's POV. If she is normal to high emotional intelligence and IQ, then she's aware that there is something that has always been going on with mom. The more people hide things, the more obvious they are hiding something big. Without a label, children grow up blaming themselves for problems (egocentric reasoning) until about the 20's, when they realize it's not all about them. They want to understand. Secrets are not always great for relationships. But it depends on the ability of another to process and handle the information and the emotions that go with them.