I think you've done better than expected. Lavinia Wood is a decent name to research. Look at the distance between the Holroyds in Sydney Street and Lavinia at Murray's Road. There's a good chance they knew each other especially so as the Holroyd's was a corner grocers. Lavinia wasn't a domestic servant as most single mothers were. She must have had some means not to be working so that matches what we know about Lavinia Wood of Murray's Road. There's no proof about the father, there's no definitive proof for the mother but the clues are all there and I think there's enough clues pointing to James W Holdroyd of Sydney Street and Lavinia Wood of Murray's Road as the parents.