Charles Ellicott Commentary Genesis 38:25-26

"When she was brought forth, she sent to her father-in-law, saying, By the man, whose these are, am I with child: and she said, Discern, I pray thee, whose are these, the signet, and the cords, and the staff. And Judah acknowledged them, and said, She is more righteous than I; forasmuch as I gave her not to Shelah my son. And he knew her again no more." — Genesis 38:25-26 (ASV)

She sent ... — The Talmud praises Tamar for so acting, as to bring no public disgrace upon Judah; and he acknowledges that he was most to blame, because the cause of her crime was his own failure to act justly by her.