What is form WR-703 Processing Sheet?
-It is Data Collection for Alien Documentation,
Identification & Telecommunications System (ADIT)
Do I still need it for filing I-485 now?
-No.
I just found out that my lawyer wrote my mom's first name wrong when filing my previous I-485, now I am filing another one using the same A number,
-I hope her name in the Form I-130 is correct. Your mother does not need to file a new I-485. Just call USCIS or go to USCIS local office to see whether it can be fixed. Your mother also can correct her name during she conducts the fingerprinting later.
should I be prepared for any trouble?
-Nothing to worry.
Thanks