Slievenaman or Slievenamoney are possibilities as per Alison. Donegall would be a fair stretch of the legs so I would rule that out as well. Is it possible the place is Donaghadee with the pronounciation slurred as in Donaghdee?. The other places may be very small townlands. I have travelled extensively around the Co Down but none ring a bell. I will contact a brother in Newcastle, he may be able to help. The other explanation may be that it is not a Co Down song at all and may well be from another part of Ireland. I suppose there could be a Legananny or two somewhere else. ?.

Slainte