Thanks for your interesting response Susanne.
Yes, Hugh Crow had a well documented son that died well before his father. However, I have not come across any research accounts that address HC's illegitimate daughter Mary, who would have been going on 13 years when her father died.
Mary is clearly recorded in the official IOM registers as the illegitimate daughter of HC and Jane Christian. Strangely, there seems to be a 'blackhole' about this matter.

I wonder what happened to Mary and her mother Jane - neither are mentioned in HC's bountiful will - and what surname did Mary take? I also wonder what happened to them both in later life.
With all the guff written about HC and his high status within the IOM community at that time, I am intrigued why researchers , family historians and genealogists have not addressed this aspect of the captain's life.
Anyway Susanne, you have just found another relative or two in your family tree. If you are related to HC, then you are also related to Mary and her mother Jane Christian.
I remain interested to get some posts from those who have conducted research into Hugh Crow and his family.