Australia Shilling

I’m entering the National History Challenge and I need to find out about an ancestor. How?
I’ve already been on rootsweb and I can’t use Ancestry.com because I’m only 14 and I can’t pay. My ancestor’s name was Mary Pardoe/Pardeaux, she was transported here to Australia under the name of Mary Barlow due to a misspelling or mispronunciation. She marrried one of the saliors while onboard and had his child while onboard. His name was Edward Scott, he left Sydney when she arrived and went to China and then to England again. And then she remarried and that’s as far as everything I know.
I wanna know where she worked when she was in England, becasue he stole 3 bits of gold and 14 shillings in silver from her master who I think was a prosectutor. This happened in around 1789-1790.
Someone with an Ancestry.com account please help maybe.
The ship was the Lady Juliana. Her child’s name was Ann Scott.
I might be able to help… but I need more info to get accurate results.
Do you know where she was born and her date of birth? Date of death?
Also, Pardoe/Pardeaux is a fairly common name… Do you happen to know about the time she arrived in Australia? Or what ship she arrived on? Did she live in Australia for the rest of her life? What area of Australia (City/County)?
Name of second husband? Name(s) of children?
1957 australian silver shilling