Write two I-130 letters to USCIS.
-Two pages straight and direct to the point.

1-Page #1 I-130 Affidavit letter from the petitioner who is a US Citizen stating to relocate with his wife, 1 boy, and 2 girls to the US for better living and education. Have enough savings for 1 year or more once they move to the US. Also has an offer letter to start work as soon as he is back in the US. 

2-Page #2 I-130 Affidavit letter straight and direct from a close family friend that knows husband-wife and kids and other family members for 10 years.