By Leo Black & Rom Preston-Ellis A farmer crawled 20ft into a tunnel stream to save two lambs from being “swept away”. Marian Porter, 26, leapt into action after noticing two animals had gone missing during her morning check of the flock. Marian and her fiance Gary Thornborrow, 33, noticed the lambs’ mother standing next to a stream that runs by the field she works at. The young farmer crawled into the tunnel, which runs underground into the river Tweed. Weather was windy and wet when the lambs disappeared on March 27 so the stream was high and swept them underground. Marian, of Peebles in the…