There is another source for Drouin records, https://www.genealogiequebec.com/en/, which is also behind a paywall.
The quality of the image is very poor, so its difficult to transcribe. I do see Joseph Mils and Marie Brun on the 4th line down, wrapping to the 5th. On the line below I can make out Celestin Pettipas and Gertrude Surette. Those are the names of parents noted consistently in the secondary records for Laurent and Charlotte
The date of the marriage is 10 February 1841 in Barachois parish, which is now in Westmorland County, New Brunswick (https://archives.gnb.ca/Exhibits/Communities/Details.aspx?culture=en-CA&community=157). So there is also an NB record, which doesn't record parents names: > "New Brunswick Provincial Marriages 1789-1950," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QVBF-V2FX : 13 March 2018), Lawrence Mils and Charlotte Petitpas, 10 Feb 1841; citing , , New Brunswick, Canada, p. 139, Provincial Archives of New Brunswick, Fredericton; FHL microfilm 846,409.
The New Brunswick Genealogical Society shows Joseph Mills born circa 1765, son of Joseph Dupuis Mills and Marie Boudrot. He married Marie J. Brun born 1766. They settled at Memramcook in Westmorland County and had a child Pierre Mills, born 1795 who married Pelagie LeBlanc.
The source (Daniel F. Johnson’s New Brunswick lineages, pg. 167-8) does not mention other children.