Based on the townlands, I doubt that either Will is for this Alexander Campbell.
The village of Garvagh is in two parishes- Errigal and Desertoghill which means a variety of possible churches the family might have belonged to (and not all records are complete or online). Unfortunately you haven't indicated what religion they might have been but I suspect Protestant rather than Catholic.
There were various Campbell families in the area and I did find a baptism for a Hannah daughter of an Alexander Campbell in 1814 (unfortunately there's a gap in 1st Garvagh records 1816-1822). There are many errors in this set of online records but I'm not at home to check my own transcripts which were done from the originals rather than from photocopies.
1814 Jan 10 Hanna daughter to Alexr Campabel of Keurn, Parish of Desartoghill
http://www.torrens.org.uk/Genealogy/BannValley/church/GarvaghP1/Baptisms/1795-1829.htmlKurin or Kewrin, just outside Garvagh, is in Desertoghill Parish.
https://www.townlands.ie/derry/coleraine/desertoghill/kurin/However, weavers at that time could have moved about a bit and later with the decline in the linen industry changed occupation to farm labourer, etc.
I should have added earlier that the 1831 census for Co. Derry does survive but gives limited detail- townland, name of head of household, number of males and females and number by religion. Here's Alexander Campbell in Kurin- 3 males & 2 females (all Presbyterian)-
www.census.nationalarchives.ie/pages/1831/Londonderry/Coleraine/Desertoghill/Kurren/2When I get home I can check my files for information which will not be online.