Glad to help
I only just slung it in for you to consider because of the similarity of the parents' first names. You coming up with a very similar maiden name for the mother looks to clinch it. As there are no siblings listed in the same batch, it is quite possible that the family moved on to Poszony soon afterwards, and that is where Jozsef recalls being brought up.
Although you have a date, if his sister was subsequently born in Poszony, you would still need to know which of the many districts it was in. It would have to be one of these which although now in Slovakia, are supplementary to the Hungarian family history resources produced by the local MACSE group. Regrettably there is no index, they are just on a browse basis.
Pozsony, Német I. rész Pozsony, Német II. rész Pozsony, Német III. rész
Pozsony, Szentháromság
Pozsony, Szt. Márton I. rész Pozsony, Szt. Márton II. rész Pozsony, Szt. Márton III. rész
Pozsony, Szt. Márton IV. rész Pozsony, Szt. Márton V. rész
Pozsony, Virágvölgy I. rész Pozsony, Virágvölgy II. rész
Pozsonybeszterce Pozsonyhidegkút
Roy G
Post script. Changes between German and Hungarian on the sister's documents MAY mean that Johanna was also known as 'Mayer von Vegh'