Magpies go into the winter break in second place after surrendering top spot with defeat at home on Saturday.
The hosts fell behind on 20 minutes when Becky Odlin scored for third from bottom Hawks.
The visitors added a second on 48 minutes through Katie Hewitt as Magpies suffered their first league defeat of the season.
They were overtaken at the top by Sevenoaks, who thrashed Bromley & Beckenham 5-0.
Magpies will now turn their attention to indoor hockey, with an East Championship in Cambridge on Sunday December 2, followed by the National Indoor League over two weekends in January.
They return to action in Women's Conference East on February 3, with a trip to Wimbledon, although they will now be without Emily Wilford and Rosie Butler, who embark on gap year travels.
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