Welcome to the boards!
Great first post, but a little clarification might help a bit here please...
Can you confirm that you are looking for Emily (or Elizabeth) ROBERTS who lived 1892-1977 and her daughter Ruth ROBERTS?
Is STEWART Emily's maiden name? Or Ruth's married name?
Could you tell us where Emily and Ruth were born please and when Ruth was born? Did Emily's husband not go with them?
Have you had a look at the passenger lists at http://search.ancestry.co.uk/search/category.aspx?cat=40
and at the Ellis Island pages http://www.ellisisland.org/
which may give more information like address that they were going to.
Also the LDS site with US records https://familysearch.org/search/collection/list?page=1&r...
has census data (some free) , BMD's, Death indexes etc
Fiona (board admin)