It depends on the lie. If it's not especially relevant or important to the case then no. i.e if WA says she was wearing a blue dress on the day of the murder, despite knowing she was wearing a red dress, then no. In the context of the book, I don't think it means much.
A good example is the case of Mel Ignatow. He lied on the stand when he on trial for the murder of his wife, saying he did not kill her. He was found not guilty. However he later admitted to her murder, double jeopardy laws meant he could not be prosecuted for her murder again, but he was prosecuted for perjury and served 17 years on perjury charges.
Which is why a lot of WA's lies in court don't mean much. However if it transpires that she knew her family were planning to kill Dan, then that will be a problem for her. She lied about her families involvement in court and in the police interview. These lies, arguably enabled her family to avoid prosecution, important lies that open the door for the State to pursue perjury charges as well as Accessory charge