Tell her that you were conflicted, did not want to meddle in her private affairs, regarded the issue as a delicate and touchy one, did not want to be the bearer of bad news - something along these lines.

Wikipedia: ""Shooting the messenger" is a metaphoric phrase used to describe the act of lashing out at the (blameless) bearer of bad news.
In earlier times, messages were usually delivered in person by a human envoy. Sometimes, as in war, for example, the messenger was sent from the enemy camp. An easily provoked combatant receiving such an overture could more easily vent anger (or otherwise retaliate) on the deliverer of the unpopular message than on its author."

The bold part is about a messenger who was actually sent by the author. In your case, nobody has sent you. So, your case is even stronger.