I recently locked myself out of my house in a robe & had my friend Jess come to help, why did she say this?

Hard one... In some ways I think she may have been trying to be funny or something. I think the comment relates to the embarrment she could cause you if she took your robe rather than it being anything ual. I think it was a joke that didn't work. Try not to get too hung up about it. You could ask her, but I doubt she will know the reason she said it in the heat of the moment.