Trying not to hurt her feelings

I am in the midst of Christmas shopping, and I wanted to buy some comfy pajamas for a friend. She has recently gained weight, and she is not happy about it.

Do I buy her usual size, and include a gift receipt? Or, do I buy her current size (and, will still include a gift receipt)?

I am buying a few other small things for her, but she recently talked about buying pajamas for herself, so I thought it would be a good gift.

Also, I would like to stay away from gift cards or money, as they seem impersonal.

Thanks in advance.