Pashuteh Yid: In Derech Sichah, which are conversations Rabbi Man, who learns with Rav Chaim K had with Rav chaim, he quotes this conversation.
Rav Man told Rav Chaim about a kiddush for an older girl he attended while he was visiting LA, which was based upon the story quoted about the Steipler. Rav Chaim rejects the story completely based upon the following.
1) He never made a kiddush for any of his daughters. (His mother-in-law did make one for his oldest daughter).
2) The Steipler never told any of his family members to make a Kiddush.
Rav Chaim is convinced that if there were truth to the story he would of heard his father encouraging Kiddaishim.
Stories about our leaders are often interchanged. It was probably a different Godol who prescribed the kiddush.