Purchasing home from a deceased family/owner

Hello! 

I am interested in purchasing a home but it seems the owners/owner is deceased. So a third party family member is taking care of selling the property. There is only an alternative disclosure available because the family member does not know what all was done to the house or could be wrong. Things I could see needed to be replaced off the bat include siding, carpet, painting, replacing appliances, etc. 

My main question is how do you come up with an offer for a home when there is not a full disclosure? Also, is there any other advice you would recommend in a situation like this?

Thank you!

Ana