Yes, their approximate ages in 1851 based on date of birth not the age in 1841 (which had some rounded down).
I am actually hoping the family is NOT there because I believe, apart from William's spouse's first name (perhaps an error in 1841), that it is my family that went to NSW in 1849:
Assisted immigrants arriving in Sydney & Newcastle, 1844-59
Surname Firstname Events Age Remarks Vessel Year Reel
SANDS William 38 and family Diana 1849 2135, 2459
SANDS Katron 34
SANDS James 14
SANDS Margaret 13
SANDS Elizabeth 11
Katron can also appear as Catharine or Catherine. Daughter Catherine born 1840 must have died before the family sailed.