Back story - my DB is divorced. Him and ex-SIL co-parent their young children amicably, and, to a certain extent, seem to make it work. Ex-SIL has a history of being controlling and, I feel emotionally abusive, towards my gentle easily manipulated brother. It seems to have got worse over the years. She often makes unreasonable demands around childcare, but for the sake of my gorgeous nephew and niece whom we all adore, my extended family and I have never got involved and always maintained a friendly relationship with her.
It's become really obvious over the years that SIL is doing less and less actual childcare. When the kids are not with my DB, they are either with specific relatives or in various after-school clubs. On a regular week, my DB says she has the kids for two mornings before school and two evenings from 5ish 'til bedtimes. Never ever consecutively. She has said she 'has had enough of them' after one evening. The eldest is starting to ask questions as to why Mum never looks after them.
Today is the eldest's birthday. The plan was to have a family meal get together at her house, as it's the kids primary residence. SIL works very flexible work hours so they arranged she would collect the kids from school then DB would go over after work for a little party. She called DB midday to say she is unwell (sinusitis) so now can't collect the kids from school (which is walking distance from her house, and so DB needs to leave work immediately to come over to hers, to 'tidy the house and buy stuff for the party tea, then collect the children from school. He works a train ride away and cannot just walk out of work. For once he refused to do her bidding, so now the party is off, also she feels too worn out look after them tonight. She regularly pulls these stunts but as my brother kept repeating to me on the phone. 'It's her child's birthday... ' She has form for getting really really angry if my bro doesn't do what she says, and she threatens to end his contact with his children.
I feel so desperately sad for my nephew and his little sister. He is expecting a family party but now that won't happen as none of the family will travel over to my brother's house. Just for the record, my niece and nephew are darlings. Well-behaved and no real trouble at all.
So after all that, my question is AIBU to think this isn't normal maternal behaviour is it?