Yew Tree Cemetery belongs to the Catholic Archdiocese of Liverpool. Some of its records are on Ancestry along with records from Ford, Litherland, the original Liverpool Catholic Cemetery which was established in 1853. It does depend on which years you are interested in though. It's in their Liverpool Catholic Burials records.
There is a long-running thread on the Lancashire board where one Rootschat member volunteers to look up grave details for any individuals whose date of death is known. It might be most useful to have a look at that.
Good luck with your search,
Joney
