According to Waïte, when Phillips was 13 years old, her half-sister Mackenzie informed Bijou of her (Mackenzie's) ten-year incestuous relationship with their father, and the information had a devastating effect on Bijou's teenage years, stripping her of her innocence and leaving her "wary of [her] father."[4]
https://en.m.wikipedia.org/wiki/Bijou_Phillips
If she didn't know, then she was probably pretty triggered by what Masterson did when it came out in court.
But also:
In 2004, Phillips began dating actor Danny Masterson;[24] the couple met at a poker tournament in Las Vegas. They are both Scientologists.[25] The couple announced their engagement in March 2009[26] and were married in October 2011 in a private castle in Ireland.[27] On February 14, 2014, Phillips gave birth to their daughter.[28] Phillips starred with Masterson in several films and in a 2011 episode of Fox's Raising Hope.
You never know with the wealthy elite class scientologists.