The Silent Lady by Catherine Cookson

The woman who presented herself at the offices of the respectable firm of London solicitors was, the receptionist decided, clearly a vagrant who had been sleeping on the streets. The clothes that hung on her frail body were filthy, and she seemed unable to speak. When she asked to see the firm's senior partner, Alexander Armstrong, she was at first shown the door - but when Mr Armstrong learned the name of his visitor, all the office staff were amazed at his reaction. For Irene Baindor was a woman with a past, and her emergence from obscurity was to signal the unravelling of a mystery that had baffled the lawyer for twenty-six years.
What Irene - the silent lady of the title - had been doing, and where she had been, gradually emerged over the following weeks as Armstrong met the unlikely benefactors who had befriended her and helped her to build a useful and satisfying life in a sheltered environment. Now, at last, she was able to confront her tortured and violent past and find great happiness and contentment with the help of old friends and some newer ones.