Approval of I-485 but not for children

[kashpants]

I applied for I-485 (employment based application/ EB-1) including for my family. We have received approval notice for me and my wife's(as dependent). But not for my children. We applied all together as my dependents. Is this situation common? why Children gets approval later??
Appreciate feedback.

[waitin_toolong]

if its been less that a week i would not get worried about it, happens sometimes, i just heard of a case where the derivative got approval a week before primary.

[kashpants]

if its been less that a week i would not get worried about it, happens sometimes, i just heard of a case where the derivative got approval a week before primary.

Dear waitintoo long,

Above was your reply. In fact its almost 6 week and we have not gotten my childrens approval. Throught my lawyer, he found that children cases were separated than me inside USCIS. My concern is we applied as family, we did all medical & fingerprinting all together. Me and my wifes approval got at same time 6 week before. Why children cases only are separated. Is there anyway we can claim/follow-up with USCIS. Ours was under EB1. Due to this situation, do you believe that childrens cases were placed in different category?? appreciate your advise.