Friend keeps trying to wear my clothes

DEAR HARRIETTE: My friend, who is significantly heavier than me, keeps insisting that we're the same size. I don't think she means to offend me, but she's a very large person, and she probably has more than 50 pounds on me. I don't mind that she's heavier, but what bothers me is that she keeps trying to wear my clothes and acts surprised when they don't fit her.

I'm not sure how to approach her abo…