What’s the best way to show a client they’re completely lovable and worthy?

My client has been told and through actions of others (including sexual, emotional, and physical abuse) for more than 6 decades that she wasn’t enough, she was unlovable, etc. She knows logically this isn’t true, but internally she can’t bring herself to believe it. Is there a worksheet I can give her, or some other way that would help me help her realize she is completely lovable and worthy?

She wants to believe this, but her thoughts go back to what others have programmed her to believe.