She received political asylum in 2008 and applied for her GC in 2010 with other family members. The other members got their GC saying they are residents since 2008 but hers says since 2011.

Yes, her LPR sttaus should be from 2008. Although she needed to wait anothre year to file her applicaion for adjustment of status, her LPR status retroacts to hen she was first granted an asylee status. This is important as it will have an impact as to when she can file for naturalization. We can certainly help in requesting this correction.