I misspoke. Her attorney did not say "joint" ownership. He said a form of ownership. Correction. There were three parcels initally from mom's estate. Two outright to each separately and the subject property was deeded as to a 1/2 undivided interest to my client, Linda and 1/2 undivided interest to her brother Jeff. This I understand as tenancy in common and was used specifically to prevent Jeff's widow from ever having any ownership if Linda died before Jeff, then Jeff, leaving the widow owning the property with Linda's trust beneficiaries. This was deeded this way as to exclude the rights that JTWROS has. Mom hated the widow as much if not more than my client did. The life estate was  written ASAP after an agreement could be made. Jeff had quit paying his share of expenses as the widow was controling the money. Then a new deed was recorded as follows: Jeff, a married man as his sole and separate property, as to a life estate, and the remainder estate to Linda, an unmarried woman.  

So because he had original interest, albeit an undivided half at the time of the life estate was created, should not the remainderman, Linda (beneficiary) gets the step up as to the entire basis just as she would have had the ownership been JTWROS?

I'm an old CFP®. I've asked my two best CPAs here, one of which is a tax attorney, locally for an opinion. They both told me. Yeah. I don't do life estates. Nobody wins.

That's not always true. The widow, when Jeff lost his mental capacity, had the ag well capped off on this subject property, dug one on the property Jeff owned outright (which she would inherit) and piped water from it to the fields on Linda's land in clear violation of the life estate. The diminished value is estimated close to $1,000,000 or more as water becomes more precious. Linda's investing $300,000 to did a new hole, fight Environmental Health and the USGS for an EIP which may or may never come before she can dig.

Plus the bonus of suing her former sister in law for damages, wasting, entering into unlawful contracts with POA acquired thorugh a young unscrupulous attorney willing to ignore the fact that Jeff had severely diminished capacity. This was done after the long time family attorney said no to the POA.

Best Linda can hope for is a lien against the property with the well the widow has inherited and still is delinquent on paying taxes. Judge will not have a lot of sympathy. She walked away and never invoked her rights for annual inspections and examination of records. Oh the life of a tax professional....