i called the USCIS customer service and I have been told that she is not sure about it.. LOL
she recommended to visit USCIS local office.

Further I asked How about the I-130 fee?
Since, I can include my child in my spouse's I-130 as according to the I-130 instruction, should I have to pay fee only for my spouse's I-130 or I have to pay fee for both my spouse and my child?
- She said she is not sure about it either..

Now my confusion is increased.