My husband step mother passed away one month ago. His father passed away more than 20 years ago. My husband was 5 years old and his brother was 3 years old when their father married their step mother. After their father's death, their stepmother remarried and communication among the parties ceased for a period. In the meantime a caretaker came into their stepmother life caring for the stepmother and her husband. The stepmother had a severe case of diabete, could not walk and was blind. When I met my husband stepmother and her husband, we were newly weds and he was beginning to commuicate with his stepmother again. Shortly after their reunion, she was placed in a nursing facility and my husband brother also renewed his relationship with her. My husband brother was only 3 years old when their biological mother passed away, so she were more than a stepmother to him. After their stepmother passed away, a surpise will surfaced with the caretaker being the executrix. We feel as though the stepmother was brain wash into executing this will. A few months before she passed, she told my husband, their were policies will to him and his brother. My question: can my husband and his brother contest this will?

. We feel as though the stepmother was brain wash into executing this will. My question: can my husband and his brother contest this will?

Probably yes, but your husband will be obligated to prove by clear and convincing evidence that she was EXACTLY brain washed.
It is not unusual a caretaker to become an executor.

Second point here-as stepchildren your husband and his brother are not automatically entitled to her inheritance.She could leave a legacy to anyone.

First life insurance policies are not "willed" they have a named person who the insurance company should pay directly, Life insurance unless there is someone named to receive the money does not go into the estate and the person doing the estate has nothing to do with them, except to notify the person of the policy if they find it.

Next of course step children have no real legal right to an estate. They may contest, but other related family would have a much better claim.

Also being the exector of the will does not mean she will even get a penny ( beyond fees for doing it) I have an attorney to do mine to give out things to family members.