this was a Roman Catholic baptism - there another MacNally bapt in 1836 + 2 non-catholic in 18938-1841 - prob not related as IoM was often a staging post in exodus from ireland - actual reg gives the godparents (sponsors) John Connor + Matilda Carty - also noted 'of Douglas'
The latter is a widow head of household in Sand St (today's Strand St Douglas) - John Connor is noted in 1841 as irish born with ?wife Rosa in School lane Castletown thus the of Douglas prob refers to Matilda - Castletown was the military centre as the only barracks was there - John died in 1848 but in 1851 wife Rosa was widowed Publican living in Queen Hive St (now Queen st) Castletown - I'd look into a possible military link
The actual wording is somewhat different from that of the children of married couples ? if illegitimate child?
The priest was Charles Aylmer S J (a Jesuit from Dublin - look up RCath parishes on www.manxnotebook.com