I suppose it depends to a degree on what actually happened in the house but it's hard to imagine her aggressively forcing her beliefs onto the family – so I imagine she just brought it up and it seems a shame that we have to watch what we say so much in case someone's offended. Would this be the same if someone at my office offered to pray for someone else at work who was ill?
Or does it have to be their official role? I mean you couldn't complain about a priest offering prayer could you? Object, perhaps, but not lodge an official complaint. Many priests see it as their business to visit people in their parish and offer assistance to those that might need it.