USA can this 21 year old girl claim her brother

[DDaccountant]

she meets all the tests to claim her brother, I know that generally they have to make more money than the parent in order to do that, but her mom already claims her 3 other children, and the mom made AGI 11700, while the daughter made 10700 ( the one I am asking whether she can claim her brother). could this cause any trouble? I mean the taxable income of the mother is lower, and the mother is already supporting 3 kids

 

[kirby]

If she indeed "meets all the tests to claim her brother" , then she can do so.

 

[DDaccountant]

If she indeed "meets all the tests to claim her brother" , then she can do so.

Well she meets the residency, relationship, support, but her AGI is $ 1000 lower than the mom's. but the mom is already claiming 3 other kids.