>> Nothing indicates that she has been leading him on or has promised >>
Errmm .. oh yes she did. Read the words of "The Unkind Shepherdess" and you will see that she promises him that she will return to marry him when she returns from her stint in service ... but then turns round and goes back on her promise because she's living a cosy and contented life and doesn't want to be a poor shepherd's wife. In all my years of singing the song, she's always struck me as a rather shallow and fickle little thing!