Where exactly did the Angel salute the Blessed Virgin before the Annunciation?

We read about the introduction to Annunciation in Lk 1:28-29: > And the angel came in unto her, and said, Hail, thou that art highly favoured, the Lord is with thee: blessed art thou among women. And when she saw him, she was troubled at his saying, and cast in her mind what manner of salutation this should be. Note the words "she was troubled at his saying". Luke does not say that Mary was taken aback to see a male stranger suddenly standing in front of her. Now, most of the images depicting the Annunciation show Mary kneeling down in contemplative prayer in a room, purportedly her at home. But, wouldn't she be startled to see a man appearing before her in the safety of her home? Is it possible that she was outside, tending the garden, or drawing water, or caring for the domestic cattle, or even shopping? Out of her home, she had the chances of meeting a stranger and not getting afraid. Or, is it possible that Mary had an intuition of the ensuing Annunciation, on account of which she was spending time in prayer and contemplation, remaining mostly at home? My question is: Are there any extrabiblical writings on where Blessed Virgin Mary was, at the time the Angel addressed her before the Annunciation?