why の goes with other particles except に?


I have seen の joining with で, と, へ and others to form a relative clause, but
never with に, why is that? Logically, shouldn't it be possible as well? For
example 彼女への手紙, how do you say it but with に? is it just 彼女に手紙? but then I
feel like it's missing a verb here.

