Elizabeth,
Yes, I have located your Harriet Hughes age 11 on the Sheridan passenger list. This may shed some light on Hariet apart from what you have.

Harriet is located on the first page of the passenger list. Apparently she was traveling with another family as at first scan, I find no other Hughes names on the list. Some of the handwriting is hard to read but for the most part is ok.
Here is what is listed. Harriet apparently was traveling with Archibald Beattey and family.
Archibald age 39, ( looks like W ) Beattey age 37, John Beattey age 13, ? Beattey, age 9, Ishbella Beattey age 7, Thomas Beattey age ( ? 5 ), Betsey Beattey age 3, Harriet Hughes age 11.
Archibald Beattey - occupation is listed as " Gentlemnan, Great Britton". As I understand, he would have been someone of means that did not work at a trade.
Does the Beattey name fit into your family line? There must be some connection for Harriet to be traveling to America with this family. I hope this helps. I can send a copy of the actual passenger list if you like. I was able to find the microfilm of the list at the Western Reserve Library in Cleveland, Ohio.

Roy