If I file a wrongful claim in the death of my husband, what does an attorney need to prove on my behalf to allow me to get compensation?

There are really only two main things that a plaintiff filing a wrongful death claim needs to prove when they file a wrongful death lawsuit:

That you are a statutory beneficiary of the deceased — e.g. parent(s), spouse, children

That your family member’s death was the result of the named defendant’s wrongful act(s)