The only ethical way I can think of is that of Elizabeth requiring permission from her advisor and explicitly acknowledging the contribution of Rose in the preface and in the chapter where the literature review appears. For instance,

1. Introduction

(§1.5 by Rose)

The only ethical way I can think of requires three steps from Elizabeth:

1. checking if the university rules allow such a contribution;

2. speaking with her adivsor to see if they, too, permit such a contribution, and if they think whether the examination committee might like it or not;

3. explicitly acknowledging the contribution of Rose in the preface and in the chapter where the literature review appears; for instance,

   1. Introduction

   (§1.5 by Rose)