Maybe the question I should ask is where did OP get the blanket when she took it out of storage? If she took it from the Aunt's house without the Aunt's permission then yeah, I'd agree with you. But OP worded things very casually when it comes to where she got it, so I assumed OP had permission to go through whatever storage she went through and to borrow whatever she found there. Maybe it's just a difference in family life, but my family does have communal storage for old gear that any one can use and if she had a similar set up then it would be more understandable that she borrowed it and didn't think it was significant. She still shouldn't have given away anything that didn't belong to her, but I guess I would find it difficult to consider her an actual theif if she took somthing from ye olde communal family stuff and gave it away—then she's just an asshole. And she should be allowed to appoligize, replace or pay for the thing (if she can find a replacement) and move on. This is a blanket OP's aunt had in storage, not money from her purse, so yes, calling her a thief does seem overblown here. However, if it is the case that OP went into the aunt's house and "borrowed" shit without asking and then gave that away, I would agree with you.