I have a one-year-old myself, so I know how this goes a little bit...
Some people do have problems with it, some don't. I give some major points to anyone willing to show an interest in a person with a child, and include the child in the interest. Buying things... thst would make me a little uncomfortable. But playing with my one-year-old, talking to her, maybe saying hi every so-often or whatever; people like that are extremely impressive.
You don't have to consider it a 'Mother with Child' package really... you could just be with the mother and have the relationship that way. Not everyone is looking for a new 'father/mother' for their kid. Some people with children might prefer the relationship seperate from the child.
I guess it just really depends on thw two people involved. I don't think it's a bad thing to have an interest in a single parent.
Though more often than not... I would think that people do have some issues with single parents. Whether they bring the child into it or not.