I'd venture that most, if not all, people have experienced some Adverse Childhood Experiences. However, many have protective factors that mean those experiences are dealt with in ways that increases resilience and do not result in unresolved trauma.
For example, somebody may experience a close relative dying. With strong protective factors, such as one or two loving parents, a supportive wider family, good, caring, well resourced school, a secure and good condition home and adequate income to meet their physical and emotional needs, it becomes a sad bereavement that they come to terms with.
However, add in the loss of that person meaning a parent was unable to care adequately for them, abuse, poverty and insecure or inadequate housing, a long drawn out and painful demise or a sudden death in the child's presence, lack of support from school, bullying, illness, disability, SEND not being identified and handled adequately, a loss of friends, further bereavements, experiencing systemic discrimination such as for ethnicity/faith/now being in a single parent or no parent family, etc - and the continuing tally of ACEs result in unhealed trauma wounds that can carry into the next generation as well as throughout adulthood.
Sounds like your DW cannot see beyond her own trauma, which is what multiple ACEs can do to somebody. And instead of gaining insight that whilst most people do have sad or unpleasant things in their childhood, some don't (lucky them - and I mean that, that's great) and some do, but they are adequately supported to develop that resilience, possibly because they experienced a smaller number in all.
At the moment, she's using the accusations possibly because she cannot imagine that somebody can't have experienced everything or because she's looking for reasons to justify her continuing exactly as she is whilst you facilitate her not making that scary change to how she sees and responds to life. And she's probably at best envious of what you do have whilst being resentful that she doesn't, so it's safer in her mind to denigrate it because then it's not such a stark difference between what the two of you experienced. 'I didn't want it anyway, it's shit and all fake, anyhow' when it's something she desperately craved as a child and still as an adult.
It could also be that she thinks if you realise from your support that this is not a healthy situation - where she controls things - that you'll stop enabling her, which is a threat; your positive relationships are a threat to her position.
Do you have to remain in that situation if it's making you unhappy? No, not at all. You're not her therapist and you don't owe anybody that. You also don't owe her practical, physical, financial or emotional support to stay as she is - or to change. If you look closely at the exact dynamics in your relationship, could they be one of rescuer and victim or controlled by the fear of reactions? Could they, if you take out the sex of both of you and look at it purely in terms of behaviour, not sex, be interpreted as an abusive and coercive relationship such as described in Why Does He Do That? Does she only stop once you cry and then say it's your fault and you're reacting wrongly because of your 'failure' to accept your loving parent is actually not loving? Looking at it dispassionately, does she benefit from you losing the external support and care if you reject your mother? Is your relationship with your Mum an obstacle for her to overcome?