How does a spouse change her status after her husband dies for change to widows benefits

He needs to go into a local office and apply.

So if the husband is getting benefits...puts her child on there whom isnt his....they stay split up for the past 2 years....then he shoots himself. Shes has a BF for months. My child with him has been deprived bc of this deviousness. What can I do? Is there anything I can do? I want it all ..if that's what my daughter is entitled to. With a man 10 years while he made that money. She been around half that time. 5 yrs at the most. She also gets 1200$ a month in CS from.her ex.....so.i would believe her daughter already had a provider.