So I need you guys opinion and getting an opinion from a legal standpoint is even better.

Mrs. K got married to Mr. B. Before the Marriage Mrs. K had a daughter who bears Mrs. K maiden name. The daughter lived with both Mrs. K and Mr. B as their daughter till they passed though there was never an official adoption. Mr. B and Mrs. K never had any child together.
Before Mr. B died, he gave “their” Power of Attorney. In his Will, he stated that Mrs. K is his sole beneficiary to his Estate but unfortunately she died before him and he was too sick to update the Will.

Question: Does “their” daughter have any legal claim to the property? Since he didn’t die intestate.

sinistermind:
So I need you guys opinion and getting an opinion from a legal standpoint is even better.

Mrs. K got married to Mr. B. Before the Marriage Mrs. K had a daughter who bears Mrs. K maiden name. The daughter lived with both Mrs. K and Mr. B as their daughter till they passed though there was never an official adoption. Mr. B and Mrs. K never had any child together.
Before Mr. B died, he gave “their” Power of Attorney. In his Will, he stated that Mrs. K is his sole beneficiary to his Estate but unfortunately she died before him and he was too sick to update the Will.

Question: Does “their” daughter have any legal claim to the property? Since he didn’t die intestate.

Before the eyes of the Law the daughter who lived with them is considered theirs and therefore sole survivor.
Now for a twist. Let's say that the husband is alive and both daughter and step-dad are not on good terms. The judge will likely split the estate . Being that she is only heir of the woman. And Mrs K is no longer alive, It should fall to the daughter.
P.S - Why not pay a Lawyer and get this as a fact.