My mother, I suspect, is some level of narcissistic. She can be generally okay, and even nice to be around on occasion, but if there's a hint of her being in the wrong, she becomes exponentially more defensive.

"Never happened" is one. She'd claim that the the event of her doing wrong – calling others names, sabotaging others' performance, behaving in an immature, passive-aggressive kind of way – never happened. "Yeah, it did" is met with further denial. Maybe she'll admit she did that, but only because it was justified: maybe she felt so bad she could do nothing else, or maybe someone forced her to behave badly.

In general, her negative traits are flung under the rug, and her positive traits are put under the limelight. She would never admit to not knowing things, unless not knowing things puts the responsibility for the failure away from her. She'd also claim how good at <something> she is ("I'm such a good psychologist! I understand people so well!"), and any attempt at countering her positivity assertions are dismissed passively.

I suspect her faking illness – presenting herself as ailing to gain attention and sympathy, which becomes self-fulfilling bullshit – also has something to do with the perpetual-victim mentality that underlies narcissism.

This is usually referred to as gaslighting, which you may know.

A Narcissist's Prayer

That didn't happen.

And if it did, it wasn't that bad.

And if it was, that's not a big deal.

And if it is, that's not my fault.

And if it was, I didn't mean it.

And if I did...

You deserved it.

After learning about the narcissistic prayer and having siblings and my SO tell me that they thought my mom has it she proceeded to pretty much say this exactly after wiping her wet hands off on my shirt in the kitchen when we were visiting. Just remove the 'you deserved it'.

I asked her to not open our private mail when we were moving and had to redirect it to my parents (no other relatives nearby) and after doing so she threw a fit and threatened to kill herself on a main street in the capital rather than to say that she was sorry to my SO for opening all out mail.

She even sent me photos in a fit of rage proving that she knew the mail was fine to open, because it said it was just a bill for the redirecting in one case, something that was only visible from the inside after opening.

Using you as a 'sidekick' so that they can bask in their reflected greatness.

They prop up their self esteem by surrounding themselves with people who provide them with admiration.

Often narcissistic people are exceptionally talented, successful or intelligent, so they are able to get people to become their followers.