There is a long gap between the marriage in 1817 and birth of Jane in 1823, so there were probably 3 or 4 other children whose baptisms were not recorded.
Also his age at death is recorded as 67 in 1857, which if accurate gives a birth year of 1789/1790.
The transcription of the 1841 census lists (not in the order below)
John Taylor, 50, spirit merchant
Jane Taylor, 50
Jane Taylor, 20
George Taylor, 15
Marjory Taylor, 15
John Taylor, 10
all born in Aberdeenshire.
Adults' ages in the 1841 census were supposed to be rounded down to the nearest 5 years. So assuming that these ages are correct, John and Jane were born between 1786 and 1791, Jane jr between 1816 and 1821, George and Marjory between 1821 and 1826, and John jr in 1830/1831.
The index at Scotland's People lists the baptisms of George on 4 April 1825 and John on 5 April 1831, so their ages are accurate in the census. Both were baptised in the parish of Old Machar, which is one of the city parishes in Aberdeen.
The Jane Taylor baptised on 12 September 1823 was at least two years younger than 'your' Jane jr, and was baptised in Peterhead, father John Taylor, mother not named. You must not assume that this is 'your' Jane Taylor, just because she was born in the same county and was roughly the same age. There are many people whose baptisms are missing from the available records, and it looks as if 'your' Jane jr and Marjory are among them.
This Jane Taylor was one of 5 children baptised in Peterhead, father John Taylor, no mother named: Jean 1817, Margaret 1821, Jane 1823, John 1826, Joan 1827. (Not very original naming, as Jane, Jean and Joan are all feminine versions of John!) In the 1841 census there is in Peterhead a family consisting of John Taylor, 50, merchant seaman; Margaret Taylor, 50; Jean Taylor, 20; Margaret Taylor, 15; and Joan Taylor, 14. In my opinion the Jane Taylor baptised in Peterhead in 1823 is much more likely to have been a child of this family who died young than the daughter of your John Taylor and Jane/Jean Walker.
The transcription of the 1851 at FreeCEN lists at 215 Barron Street, Aberdeen Old Machar
John Taylor, 60, spirit merchant, born Aberdeenshire, Aberdeen
John Taylor, son, 19, house carpenter, born Aberdeenshire, Aberdeen
Marjory Taylor, daughter, 27, born Aberdeenshire, Aberdeen
Therefore you can concentrate your search for his birth to Aberdeen itself.