Ahoy there! May I come aboard too? Currently drifting on a raft of my own construction. Well stocked with tea and gin but would love some seafaring company.
Long time lurker here. LC but considering how I might deal with NC.
DM is a narc, had a traumatic childhood (EA and beatings, EA/SA on/off type relationships as an adult). Our childhood was awful too but we can't mention that, as her life has been so hard for her. She'd always talk about how she never hit us as if this was a real luxury (and actually she did smack me) There is a 'funny' story she used to tell about how when I was tiny I'd said I was an unhappy child. I guess she realises this might not look good for her now, or I might not laugh any more, or she's just forgotten what an inconvenient and ungrateful child I was, she doesn't tell that one now.
She was always so miserable. I felt so relieved if she had friends or a boyfriend to visit because she'd be friendly and functional and make regular meals and take us out etc. My sister was the GC and me the SG. It was baffling when my sister kicked off about my mum having boyfriends- what was there to be jealous of?
Us kids contributed to her problems as she had to look after us as a LP. I wished I didn't have to live with her. (Tho of course as we were at our dads a lot she got more time away from us than many parents do
)
There are so many things you've all mentioned about your DMs that is the same: preferring sympathetic strangers to family, playing off family members, grandiose but falsely modest, seeking reassurance but throwing it back in your face unpredictably. Using (unasked for) gifts, money and affection for control.
My DF has traits of narc, but now makes an effort as a GP so I am more willing to forgive him. HIs wife is a nice GM and with her encouragement he provides qualified support or material things for his step and grandkids that wouldn't have registered when I was a kid. (Like taking an interest in their schoolwork- though this comes with a price about his specific academic expectations for them..) he's not had a complete personality transplant. 
My DPs split up but remained in conflict e.g. interrogated us about the absent parent's love life, employment status etc etc. Never have either asked how we felt about any of it, we had to support them in their tirades against the other. We couldn't have needs or feelings. I would not reveal information out of loyalty and guilt towards the absent parent and fear of the consequences. My DM would tell me to lie eg if my DF asked about whether X was living with us/her.
I now lie out of guilt quite often, have trouble making small talk and have no idea about normal friendships. I avoid social media apart from anonymous MN as I am anxious not to reveal personal stuff. I am conscious of putting people out or being annoying so could never eg call a friend just for a chat. only to make an arrangement. I need 'an excuse'. I'm a shit friend.
I could never bring any friends back to my mums as she was so wierd. I occasionally did to my dad's but he was wierd in other ways so that stopped once I reached about 10 years old. I couldn't ever tell a friend why I was so closed off. Having friends round still feels so exposing tho I am trying to do it more now to get over it.
Doing NCT etc it was bizarre to me how everyone else so casually dropped in on each other. I got myself kind of adopted into friends families as a teen, which got me into trouble at home.
The lack of money was a massive issue growing up. what 'I cost' made me very self conscious, my mum complained about how little money my dad gave her, and my dad complained about how much money 'he had to give my mum'. I am now incredibly anxious about spending or 'costing' money, taking too much food/wasting food, taking up space, anyone's time. (Ironic given the length of this post, right
)
Neither parent has ever said they loved me, no physical affection and I try to avoid intimacy now. In early teens I had a nervous breakdown; mild depression ever since but these days more anxiety than depression. (Yay!)
As PP have said, no talks (or knowledge/interest) about my friendships, sex or relationships, puberty or periods, no supplies. I sorted it all out myself in secret with my pocket money, first bra, pads etc. My mum specifically told me not to take her pads or toiletries although my sister was allowed to and was bought them by her.
obviously I bought my wedding dress by myself etc (only just realised that might not be the norm)
I put myself at risk looking for affection and attention as I grew up. Luckily found my lovely DH fairly recently, thank god for him, probably we bonded in part due to his shitty childhood also.
I am desperate not to go the same way as my DPs or PIL now I am a parent. It's dawning that 'my normal' for parenting and for being part of a couple is batshit. My DM is not redeeming herself as a GM as I had hoped and is making me feel crappy.
I over compensate on affection for my DD but worry more about providing DD with routine and appropriate discipline.
Anyway me me me. Sorry for the GINORMOUS post, I felt it's finally time to de-lurk and didn't want to miss this boat. I'm up in the deckchairs area cutting up the limes for gin if anyone wishes to drop by.