21 year old rule for sister's daughter

[jsjz]

I am applying GC for my sister and her family. My sister's daughter is 18 years old now, so she can be included in the same petition. I know this process can take several years, so when everything is done, she will be more than 21 years old for sure, will she still be eligible to get the GC then?

Thanks in advance,
jsjz

 

[cherr1980]

Please read:
http://uscis.gov/graphics/howdoi/agingout.htm

I think since she will be a derivative beneficiary she will be subject to the formula.