Mattel Katz - Was Mattel Katz indeed the daghter of Jermias Katz and Malvin nee Berger?

Mattel Katz was added to the tree as Jermias (Emil) Katz and Malbin nee Berger daughter based on a list of Ujfeherto headstones generated by HFPJ Avosseinu when they recovered the cemetery.

On that list, line 512 reads Mattel Daughter of Yermiahu Katz d. 21 Shevat 5668.(24 January 1908)

Looking up FamilySearch, Ujfeherto death records for 1908 are missing. An acquaintance of mine searched the 1908 records in Nyiregyhaza Archive but couldn't find Mattel Katz death record. I couldn't find birth records of he either.

I have some 400 photos of Ujfeherto cemetery headstones. I was unable to find Mattel's there. Perhaps the stone had toppled at the time lapse between the lists and and the photos, or I am missing some headstones photos.

Mattel alleged siblings were born 1905, 1907, 1909 and 1915 (my father). She might have been born in 1906, but there are no records to support that.

Malvin Berger was Yermihau (EMIL) Katz's second wife. His first wife was Mari Steiner (not shown on Geni family tree). The marriage took place on 9 March 1903 in Nadudvar. Mari passed away on 9 January 1904.

Perhaps Mattel was Mari nee Steiner and Yermiahu (Emil) Katz's daughter.

Well, I searched Ujfeherto 1903-1906 and 1906-1915 birth record in FamilySearch and there is no mention of her birth.
I also looked at Naduvar records in FamilySearch and couldn't find her.

How can the mystery be solved?