Draco snorted when he saw the letter. Obviously Theo didn't understand about Gryffindor and about caring for other people. He had already let Severus inside the house and had no intention of locking him out until it was necessary. He also would do what he could without endangering his family, but Theo was never good at taking risks, so he wouldn't get any of that.
Theo,
Parvati wrote me and assured me that she would take good care of the shop. I think you are underestimating her stubbornness if you think I can persuade her. She's a Gryffindor and she will do what she must. I don't think you can change her mind regardless of what you say. Besides she would never leave her friends. Strange concepts to understand, but nonetheless true.