oklahoma estate law(no will)

My wife lost her father this week,he had no will,what are the steps that occur now?He has a small house and 4 or 5 acres appraised at roughly 68,000.He has 4 living heirs,(his blood daughters).My wife is the oldest,she wasnt with him for long ,he remarried and had 3 daughters with another woman,this woman also had 2 daughters from a previous marriage.He did not adopt them though.He divorced this woman several years ago,and died single.He also has an older brother and sister but i dont think they are Heirs.What do we need to do to make sure that my wife is included in his estate?Any way the other children can exclude her?Thanks in advance for your help!!