I think the brother will get the lamp at some point..

But does it matter if he gets it now she's not in it anymore and csnt she choose if she grants wishes. With the boy she only did one wish and went back in the lamp.

also she didnt grant the boys wishes properly either, like she used the 2 other wishes to transport people away from her. So I don't think she's limited to actually granting their wishes, she's choosing to

Hopefully that's true just in case