From Monarchists.Wiki

Sapphira was a wife of Ananias. Joseph (Barnabas) sold a field and gave the proceeds from it to the Apostles. Ananias also sold a piece of property but he secretly withheld a portion of the proceeds from the Apostles. Peter confronted Ananias about this and told Ananias, that not only did Ananias lie to the people but Ananias lied to God as well. Ananias fell dead after hearing these words, shocking witnesses. They then buried the body.

Sapphira was in on Ananias' scheme, and Peter confronted her while she was still unaware of her husband's death. Peter asked her how much her husband made by selling the land, and she repeated the false number used by her husband. Peter castigated Sapphira for lying to him and told her that she would be dead as well, and Sapphira fell dead as well.

The persons who had buried her husband also buried her, and the people of the church recognized the miracle.

Now after an interval of about three hours his wife came in, not knowing what had happened. Peter asked her, Tell me whether you sold your land for so much? And she said, Yes, for so much. Then Peter said to her, How could you two have agreed together to put the Spirit of the Lord to the test? Look! The feet of those who have buried your husband are at the door, and they will carry you out also. And at once she fell down at his feet and died; and the young men came in and found her dead, and they carried her out and buried her beside her husband. And great fear and awe gripped the whole church, and all who heard about these things.

— Acts 5:7–5:11 (AMP)