Is there any kind of assistance for children who's father is in prison serving a life sentence

In what country, China, France, Canada? We are an international site.

In the US, if the family is low income, there is normal welfare.

In general there is no "special" aid or help with the exception that some local areas may provide counseling.

Is the family current receiving any welfare benefits?

Depends on what kind of assistance you are seeking, and the location. Please specify.

https://www.inmateaid.com/family-services

NICIC.gov: National Institute of Corrections

What kind of "assistance"? Probably no more than any other similar single parent case.
Not sure why incarceration should be treated any differently.