Wow, I think my DM might actually be a narc...
I can totally relate to so many of these - the fake cancer stories - and when she finally did have cancer she MILKED it, and told everyone it was inoperable (it wasn't, and she's fine now),
and this - standing outside my bedroom door at midnight, making loud, fake sobbing noises in order to emotionally manipulate me. Just bizarre and performative - when my dad left, she used to wander round the house wailing and fake crying hysterically. Every fucking night. When I moved out at 18 with my then-boyfriend, she cried and said I was abandoning her.
When my grandfather died (dad's dad, they had been divorced for over ten years), she insisted on me taking her dress shopping as if it was a prom, and then on the morning of the funeral did a sort of fashion show thing, saying "I'll definitely be the belle of the ball!" Er, yeah Mum, it's a funeral...? 
On my wedding day, she left me on my own for over an hour as I had to go home to bf 6 month DD and put her to bed - because she was too busy doing "Mother of the Bride" duties.
Definitely with the "you got 95% on a test - what happened to the other 5%?"
When I'd just had DS, and was suffering from PND, and massive sleep deprivation (he was allergic to everything and screamed every night), obviously hadn't lost my baby weight, she called me grossly overweight (I was a 12/14).
Every time we have a meal together she makes a point of saying "Oh I can't possibly eat that much... I don't have much of an appetite."
My entire life, she's been obsessed with weight, and not eating much, and I think it's directly down to her that I've struggled with eating disorders since I was 15.
She thinks my DD is a complete incarnation of herself, and barely gives DS the time of day. She'll shower DD with presents and then be like, "Oh sorry I forgot about DS." DS asked me the other day why his granny didn't love him.
I was about to write that there was a flip side - her generosity, her caring, but then I realised that that too is a careful manipulation. She used to do things for me without being asked, and then make me feel guilty because I'd put her out. Even though I'd much rather she hadn't done whatever it was.
I'm sure there's loads more but this is getting long!
Thanks, this has been really cathartic.