https://www.womensaid.org.uk/ — Their information and support segment is resourceful.
One of the first steps to preventing abuse is to know that you are being abused. They seem to have included a quick pop-quiz to help women realise this. Although the quiz is specific to domestic abuse, it is quite useful.
I’m worried about someone else segment — https://www.womensaid.org.uk/the-survivors-handbook/im-worried-about-someone-else/
Your legal rights — https://www.womensaid.org.uk/the-survivors-handbook/your-legal-rights/