A colleague scholar was an editor for my latest published article, in which I heavily used her work and cited it. She then sent me a piece of hers to review informally and give her my comments on it. At one point she writes something and gives citations. One of my articles could be perfectly cited here. Is it ethical to suggest that she does? And how should I go about asking her? Directly in my comments to her paper?

A colleague scholar was an editor for my latest published article, in which I heavily used her work and cited it. She then sent me one of her papers, so I could review it informally and give her my comments on it. 

At one point in the paper, one of my articles could fit perfectly as a citation. Is it ethical to suggest that she does cite my article? And how should I go about asking her? Directly in my comments to her paper?