I've just blown my lid at DSis.
Yesterday, whilst at my mum's mentioned to my sister that the next time DM has her son overnight that she might like to make plans with me, as she never does.
She asked what I meant and I explained that I felt she never contacted me unless she needed something money/lift and she certainly never initiated contact between our kids or even between us as sisters.
It's always me calling her and asking her if she wants to spend time together and when we do it is always me that pays, picks her up, drops her off as she's always 'skint'. After our conversation she said, yes she would.
Fast forward to today and she has just come to DM with DNephew (I've been here with DS for a couple of hours). She sits and starts to say that our cousin has been asking her to go round tonight and she said she will see if DM will have DNephew overnight so she could.
I lost my temper and had a go at her. I shouldn't have yelled, I was unreasonable for that. But she's said I'm being spiteful for saying this to her at Christmas. 
I explained again, that it was always me arranging things for us to do, especially with our kids, and that she only got in touch when she wanted something, i.e. money.
She still owes me a tenner from two weeks ago, when I borrowed it to her she promised she would give it me back two days later as it was close to Xmas. When I mentioned that she said I was selfish for asking for it back at Christmas. 
Anyway, that's not the issue.
AIBU to expect my sister to actually put some effort into our relationship, instead of just relying on me to do everything, and stick to her word when she says she will spend time with me?
We get on well when together, and I have always done a lot for her.