A family tree on the net (Clan Moffatt) has Ann being Ann Moffatt. While it gives no evidence for this, there are some coincidences.
A baptism at Tweedmouth, Dec 19 1793. Ann daughter of Roger and Ann Moffatt of East Ord.
Other children of Roger and Ann Moffatt include Jane Douglas Moffatt, baptized Tweedmouth 29 May 1785, of East Ord. Also Roger Moffitt, baptized Berwick on Tweed, 8 April 1777.
A Roger Moffatt and his wife Elizabeth, of East Ord, are having children baptized at Spittal Presbyterian in the same time frame as Robert and Ann Youngs children. Includes two daughters named Jane Douglas Moffatt in1816 and 1817. Robert and Ann have a daughter named Jane Douglas Young baptized in 1819.
Also claims that Ann Young (daughter of Robert Young and Ann Moffatt) married Robert Moffatt, June 1860, Berwick on Tweed. This Robert Moffatt was grandson of Roger and Ann Moffatt, by their son Robert Cashel Moffatt.
All a bit flimsy, but something to work on.
Alan.