Is it correct that if after 12 years a property has NOT been put through probate following the death of the property owner, the house in question will be transferred into the name of the person whom is a direct descendant of the deceased ( eg the son or daughter ).

The short story behind my question is my wife believes the house her father claims to own is not fully his to sell due to the fact she believes her name was in her grandfather's will. Her grandfather died over 9 years ago, so we are curious to know why the house has not been put through probate by her father if,as he says, belives the house is his to sell. What is interesting here is that there is no sign of the will for us to proof read and see exactly who owns what, so it's difficult to prove. We have even spoken to HMRC and there is no will on record. I believe years ago will documentation was held by local businesses ( or so I'm told)

My wife believes 50% of the house is owned by her father however the other 50% is split across her and her sister.

My fear here is that if what I heard is correct regarding the 12 year process around probate, my wife could lose out on a considerable amount of rightfully owned money when the house is sold.

Please help
Many thanks guys :)