What is the relationship between anne frank and margot through their letters ?

Source information for this excerpt is provided at the bottom of this answer box:

From the 20th to the 22nd of March, Margot and Anne exchanged a series of letters that Anne recorded in her diary. The main subject was their mutual affection for Peter. There was a very real possibility that feelings of jealousy could spring up between the sisters. Even worse, they could end up in a rivalry for Peter’s attention. Under normal circumstances, they would probably have talked things out, but in the close quarters of the annex, it would not have been possible to do so with the necessary privacy.

The letters between Margot and Anne reveal a touching level of concern from the sisters for each other’s feelings and concerns. Margot wrote to Anne, “So there’s no need for you to reproach yourself because you think you’re taking something I was entitled to; nothing could be further from the truth. You and Peter have everything to gain from your friendship.” Anne replied, “Your letter was extremely kind, but I still don’t feel completely happy about the situation, and I don’t think I ever will …You know how much I admire you, and only hope that some of your goodness and Father’s goodness will rub off on me, because, in that sense, you two are a lot alike.”