Don’t try to move things along too quickly. Let her hide somewhere she feels safe until she’s ready to come out. Give her nice food to eat and a clean litter tray. Let her come to you - don’t try to stroke or hold her until she’s ready for it. Learn basic cat language - narrowing your eyes and looking away is a sign of friendship. When she gets close enough, stroke the side of her face to show you like her. When you get closer, bumping noses is the cat equivalent of kissing.