(A) left “1/2 undivided common int” by (B) (A) died 2021 w/B’s name as owner.Can B’s step kids inherit or does it go to B’s kids only?

Unfortunately, this kind of forum does not allow anyone to effectively answer a specific question like yours. You have posted a lot of information, but in a complex situation it's generally necessary for an attorney to probe to make sure that ALL of the potentially relevant facts are discovered before giving any legaly advice.   Here's an example of what I'm talking about: It sounds like your father's estate was never fully administered, since you say that his name is still on the deed to the property. One question, then is what DID get done with his estate, if anything. If he left property to stepchildren under his Will, but that Will was never admitted to probate, then it could actually be too late for that to happen now, since he died in 1987. If the Will was admitted to probate but the Executor never made the appropriate transfer out of the estate, then the stepkids may have actually received rights when the Will was admitted to probate, and thereby made legally effective, but it may still be necessary for the estate to be reopened in order for someone to property transfer the property. I can't tell from the information that you posted whether the Will was probated or not, and so I can't actually tell whether the stepchildren actually inherited anything.   If the stepchildren DID effectively receive rights to the property because your dad's Will was probated, then so did you and your brother Joel. If Joel had an interest in that parcel under the Will, then his interest would have passed either under his Will (if he had one, and if it was probated), or to your mother, as his only heir (based on the facts as you state them) if he had no Will at his death. BUT, if your father's Will was never actually offered for probate, then it may be that you and your mother and brother received ALL of his property and that it did not actually pass the way he wanted it to go.   What I would suggest is for your family to consult a real estate attorney to have the attorney help your family figure out how the properties in question are currently owned, and to help the family get any needed paperwork done to clean up the title. You likely also need to probate your mother's estate, so you should also have an attorney who can help with that- you may be able to find an attorney or firm that can handle both the probate issues and the real estate issues.   Best wishes to you, and please accept my condolences on the loss of your mother.