Perhaps if you gave what information you did have someone might recognize something. It is useless to track down something you already have.
I found a bit as below.
CHRISTOPHER JOHNSTON b. Scotland ca. 1815, m. CATHERINE GRUMBLE (GAMBLIN?) (b. York Co., NB ca. 1810-1; m. 1st James Morrell), d/o George and Margaret (Myrshall) Grumble.
In Andover Parish, Victoria Co., NB in 1851 as:
Johnston Christopher M Head 36 Scotch 1833
Johnston Catherine F Wife 40 Native birth
Johnston Alexander M Son 4 Native birth
Johnston Charles A M Son 21 mos Native birth
Morrell John M Step son 19 Native birth
Morrell Margaret F Step daughter 17 Native birth
Morrell Elizabeth F Step daughter 15 Native birth
Morrell James N M Step son 11 Native birth
Morrell George Wm M Step son 6 Native birth
Morrell Catherine F Step daughter 10 Native birth
Morrell Ellia F Step daughter 8 Native birth
By 1871, 'Cathren Jonston' was in Grand Falls Parish, Victoria Co., NB age 61 years, a widow. Her children were 'Alick' (24) 'AndreW' (21), 'Willem' (18) and 'Cathren' (30) (?). Also with them was 'Willem' Morrell age 7. Nearby lived James (ca. 1838) and 'Hanner' (Hannah Dee, b. ca. 1836) Morrel, Catherine's son and daughter-in-law. 'Cathren Jonston' b. ca. 1841 was likely Catherine Morrell b. ca. 1841 in 1851. George Wm. Morrell is very likely he b. Morrell Siding, NB 21APR1845, d. Morrell Siding, Grand Falls Parish 4JUN1928, s/o James Morrell. His mother was not named in his death registration. Elizabeth Morrell is likely the same who m. George Baker (b. 14JUN1830). The death registration of her son, Adam Frederick Baker, confirms her maiden name.
Possibly Alexander was the Alexander Jonston (ca. 1846) in Grand Falls, Victoria Co., NB in 1881 with a wife, Mary (ca. 1850), and children, Henry C. (8), Charlles (6) and Edward (3). Alexander Johnston (ca. 1847) was in Grand Falls, Victoria Co., NB in 1891.
1. ALEXANDER JOHNSTON b. Morrell Siding, Grand Falls Parish, Victoria Co., NB 11MAR1848, d. Morrell Siding, Grand Falls Parish, Victoria Co., NB 16SEP1901, m. MARY POLLY McQUADE.
2. CHARLES ANDREW (ANDREW C.) CLARKE JOHNSTON b. Morrell Siding (Costigan), Grand Falls Parish, Victoria Co., NB 2NOV1849, d. Cliffordvale, Grand Falls Parish, Victoria Co., NB 21DEC1930, m. SARAH JANE BOWMASTER.
3. WILLIAM GUTHRIE JOHNSTON b. Morrell Siding, Grand Falls Parish, Victoria Co., NB ca. 1853-4.