I am an only child, and really, my extended family (those we see regularly) only consists of my aunty, my two cousins who are 12 and 24, my nan and grandad and my parents.
My aunty's dh left her when my 12 year old cousin was 2, and my grandparents, who are now in their 70s, have taken a huge role in my cousin's upbringing. My aunt works long, full time hours, and my grandparents go to her house every day, to meet her from school, and have being her full time childcare since my cousin was 3 months old, when my aunt went back to work.
While my cousin was little, we all spent loads and loads of time at my aunt's (huge) house - I would say twice a month we were there for Sunday dinner. My mum and dad went on holiday with my aunt and my cousins, and everyone really supported her. My aunt is a very successful business woman, lots of disposable income, and a real 'lifestyle' person. My 12 year old cousin was a 'surprise', she only ever intended to have one child. I think, really, now my cousin is older, she is done with all that.
Which brings me to the issue. I feel totally excluded from my extended family. Despite us having spent a huge amount of time together when my cousin was little, she barely ever invites anyone over any more, as obviously my cousins and my aunt do their own thing. It's never really been a problem, and I understand her child-rearing days are over. I get the impression she doesn't want a 3.5yo and a 1yo wrecking her house and disrupting her weekend.
But lately, well, I'm starting to feel a little excluded. She arranges family events (which always take place at her house as it's the largest) at 6pm, when our bedtime routine starts. My cousin's birthday is on Friday - she is finishing work early, but not inviting people until 6pm, when she knows damn well that we can't make it. My dd worships my cousin, and I am rightly or wrongly, a bit pissed off that it feels a little pointed. It might not be, though she hasn't told me of these arrangements, only my mum.
I realise that she was a single parent, but she has remained in the bosom (!) of all of us whilst my cousin has grown up, and I am a little hacked off that no one seems to be interested in involving themselves in my dc lives and upbringing. She has probably seen my ds about five times in his entire life. Particularly as I am an only child, and no one in my immediate family is at the same stage of life as me, I feel a bit lonely, and a bit left out. And I feel a bit like my ds are seen as a bit of a pita, which is probably true 
So, AIBU?