Told mum that DSIS was being entitled. She told me I’m wrong. AIBU?

You were very good trying to help her out. It’s a shame he wasn’t more helpful, but that’s not your fault, and what they were expecting is way above the norm. And your mother bringing it up all the time is ridiculous.

id say they you’re upset at how they’re behaving and you won’t be trying to help again if this is how they act. Tell them perhaps this is why she wasn’t offered anything. Perhaps she came across as entitled to him too. And tell them she’s going to have to harden up if she’s going to be a lawyer!

Unless your BIL has his own firm he is not going to be able to offer her a job and if he is in a big firm, even work experience outside of the formal process is hard to swing. Your mum and sister need to really read up about the realities of being a solicitor. He might be able to mentor her to a point, but beyond that will be put of his control.

You don't really get given an internship or straight access unless mummy or daddy/grandparents owns the firm.

Your mother and sister are unreasonable to keep on at you or expect anything but a phone call, they have unrealistic expectations also.

I think the bigger issue is that you all stop talking to each other over relatively minor things...bot a very grown up approach to conflict.
I don't think yabu but think communication in your family is a bigger issue

It's the sort of thing I would expect people to shrug off... he's not close enough to you to be expected to be mega helpful - certainly nothing to your dsis and its no one's fault so they should just forget about it... is lawyer- stuff a particularly hard market to crack or just down to hard work?? I mean if she wanted to work at the bbc and your bil had contacts I'd understand frustration but lawyers are everywhere!

It’s not your fault he wasn’t very helpful. It sounds very much like your mother and sister are utterly clueless about becoming a barrister or solicitor. It’s not something you ‘break into’, you have to work hard, get a degree and secure a pupilage etc. You won’t be offered a job as a solicitor or barrister because you know someone who works there, regardless of how big a job they have there.

You're right. He doesn't owe her anything.
Just because he is successful doesn't mean others are entitled to his help.
It was nice of you to set up the call, it's a shame he wasn't all too helpful. That's all there is to it.
It doesn't need to be brought up regularly.

Well they can be as annoyed with him as they like. Nothing to do with you and nothing you can do about it.
If you bother speaking to them again and they bring it up tell them to shut up and grow up.