I updated the section on the Friekers found here:
stories-of-how-any-mitzvah-or-even-just-the-mental-commitment-to-a-mitzvah-saved-lives.html
Scroll down the section entitled:
Providing a Kibbutz with a Kosher Shul (UPDATED!)
For example, Rachel reveals the terrorist were not on the roof, but actually invaded her entire home (except the mamad in which the Friekers and their neighbor hid).
And yes, the terrorists knew the Friekers were there.