[Jan_Sobieski]

Additionally…why did only SHE see Samuel and not Saul?

[fidelis]

Sheesh, read the text. Saul could also obviously see Saul because they were having a conversation. The particular reason in this case that Samuel appeared was, not because God took the initiative in sending him, but that God allowed the apparition to compound Sauls sin of having him called up.

Regardless of the particulars, the original fact remains that, contrary to your assertion, God does allow non-angels to appear to men to convey messages. Both the cases of Samuel and the Apostle clearly prove this.