I think Alphys has a second leitmotif that is used less than her first one and it isn't mentioned on the page for leitmotifs on major or minor leitmotifs (as far as I know)
In the song Alphys, it plays from 1:00 to the end of the song, the leitmotif is the entirety of She's Playing Piano, and in the unused song Alphys' Lab, it plays from around 0:59 to the end of the song. It also might play earlier in the song at around 0:19 or 0:20 to 0:39 as that part sounds really similar to it.
It is only used in three songs, so I think it'd classify as a minor leitmotif if it is one