1841 census: Dawson St, Deansgate, Manchester
HO107/569/9/27/6
Thos Clarke 40 Merchant [an uncle???]
Martha do 13
Frances do 7
Ellen* do 5 [likely to be Helen]
Catherine do 4
plus one servant
This looks likely to be the right set of girls, although for some reason enumerated (like Thomas) as not having been born in the county of Lancashire - if it is them, I wonder where their parents were? (Mother Martha would have been about 6 months pregnant with Elizabeth at the time of the census).