Hello,
I'm no specialist on the subject, but laundry work consumed a great deal of time in the middle class and upper class Victorian households - the weekly washing would take upto 4-5 days to complete. Because of lack of technology and fear of disease and pollution, the washing process was long, complicated with a lot of repetitive processes (e.g. boiling, 'blueing', rising, airing) .
Those, generally middle class families, who could not afford to employ more than a 'general maid of all work', often employed a laundress to work either 'in' or 'out' for that specific purpose.
In institutions, it was again an importatant and time-consuming job.
I did notice a few references on the net to this institution, so probably a significant part of the family income was derived from doing the institution's laundry. It would perhaps make more sense of her occupation being noted on the census, as well as the family living there. Also, if it was a workhouse at the time, it was common for the workers to live 'in', so to speak.
Just a few thoughts ...
Regards
Jonathan