This is just a suggestion, but based on what I've learned over the years. While I understand your wish to totally "own" this project, your sister won't care whether you or a long arm quilter finished it, when she's enjoying it on her bed. But hand quilting (even machine quilting) this monster will drag the process out for a long time. The time has come for you to get it finished and her to enjoy it. Had you not showed it to her, she wouldn't know about it and wouldn't be looking forward to receiving it ( and you might have the time to quilt it). But she does know about it and undoubtedly wants it. You chose the fabrics,designed it, and pieced it, and that's a wonderful, thoughtful gift. Now have someone quilt it and get it to her. And start a smaller project to quilt it you want...