Hi Donna
You mention a 15 year old male not appearing with the rest of the family.
There are a few possibilities for this -- the first being he travelled separately to the family either before or after they came -- so it might be worth checking both assisted and unassisted immigration records -- an advantage is frederick as that or fred or fk or just f is rarer than Robert. At that time folk were often apprenticed at 12 or 13 so there may have been reasons for him travelling separately. Knowing Fredrick's occupation might help find his arrival.
Being 15 he might appear amongst the single males on the same vessel rather than as part of the family.
Pre 1856 marriages are available to search for free on microfilm in many australian libraries. It might include Patrick McKInley's occupation and this together with the location might help you track the family. and those all too valuable witnesses. that said it night also just say their names.
Have you found any McKInley kids. I would imagine Patrick McKInley is not that common. An obituary for the next generation might contain info on the previous one. Also in the death index try to find mrs Mckinley without a surname but both parents first names.
Remember too that folk travelled interstate so a look at the qld or vic indexes both free on-line might be worth a shot.
Hannah Sophia might appear as Ann or Anna and as Sophie or as Mrs McKinely with or without his or her initial on trove,
Regards
pH
