Hi Edwin,
you may find an interesting story there.
I was looking at the 1891 to see if perhaps they were staying somewhere near a hospital to be near the baby while undergoing some sort of treatment, but discovered that this was not an ordinary residential area at all.
That page of the census, and at least several pages preceding that, describe the "street" as "Manchester Ship Canal Works" so it looks like it was some large encampment of people working to construct the new canal (finished in 1894).
Perhaps they were only very temporary visitors and had left the baby with another relative or friend or perhaps the baby was elswhere as it was not a safe environment for such a young child.
She may have been a "nurse child", or in hospital, or somewhere similar where her full name / accurate details might not be recorded.