I belonged to St. Mary Magdalene Church for many years. The church was on Amity St. in Homestead but was merged to St. Maximilian Kolbe Parish several years ago. They have their own cemetery at St. Mary Magdalene Cemetery, 22nd and West Street, Homestead, PA 15120.
Here is a website that shows some who are buried there. Your Sarah Brown isn't listed but one thing, the names are contributed by family members or users of the site so she may not be there yet.