Hiya Julie,
Welcome to RootsChat.
Bellow makes more sense to me than Dello as there were families named Bellow in the Dundalk area at the time of Griffith's Valuations - 1848-64. It's possible the name was written incorrectly on documents.
Michael Bellow, Newton Hamilton, Dundalk Street, Newtownhamilton, Armagh
Patrick Bellow, Kiltybane (or Lisleitrim), Newtownhamilton, Armagh
William Bellow, Platin, Duleek, Meath
Catherine Bellow, The Square, Macroom, Cork
John Bellow, Tully, Louth, Louth
If you Google "Bellow Dundalk" you'll see that there are still people with that surname in the town.
You may have problems since the adoption took place around 1935.
The Adoption Authority of Ireland may be able to assist if you've not already tried them. The Adoption Board also holds a file on each adoption effected in the Republic of Ireland since 1953.
If Lynn was from Co. Armagh The Post Adoption Team in Northern Ireland may be able to assist you.
http://www.sebt.n-i.nhs.uk They are at ... 33, Wellington Park, Belfast BT6 9DL Phone 028 9020 4500 Initial enquiries start at this point. Phoning form the Irish Republic or overseas 0044 2890 204500. Records in Northern Ireland are kept for seventy five years.
If the adoption took place in a different area in Northern Ireland the team will put you through to a person, who should be able to offer further assistance, in the relevent area.
Christopher