In all honesty I suppose it depends on how you want to be perceived in your relationship with your stepniece.
I have a step-grandaughter and I treat her exactly the same as my biological grandkids, she is a child and even though she has a full and good relationship with her absent bio Father, she lives as part of our sons life and we accept her as such. I want to be treated as her real granny and so I treat her as my real granddaughter and put biology aside.
If the message you want to send is that she is not your real niece then crack on. There is a big discrepancy between £50 and £1000. £1000 is a very generous gift for a 17yr old. What have you done in previous years, have you given her less then too?
Then I say to myself that perhaps you didn't give her the £1000 as you felt you only gave it to your bio nieces as you knew their parents didn't have the money for driving lessons and you are assuming your stepniece's bio Father did and I could see a case for that argument had you explained that beforehand, setting expectations. But intention doesn’t erase impact.
I see why your brother is disappointed in you, he’s upset about what it means for his stepdaughter’s place in the family. I think you have handled it without consideration for how this would be received emotionally. I think you have basically sent the message that your stepniece is not as important to you and if that is the message you wanted delivered, you have probably achieved it.
No-one can tell you what to do with your money, £1000 is very generous and I think you need to have a conversation with you brother about your rationale and if it doesn't stack up, you may want to reconsider the size of the gift you have given to your stepniece but when two children in a family receive £1000 each for a milestone birthday, and the third -who has been part of the family for eight years - receives £50, that isn’t a “slight difference in circumstances.” It’s a statement. Whether intentional or not, it communicates:
- You are not equal to them.
- You are not my responsibility in the same way.
- I don’t see you as part of the same circle.
And once that message is delivered, you can’t un‑ring the bell. Even if you now try to “top up” the money, it won’t erase the original choice. It will look like damage control, not genuine inclusion