I can't be sure, but I have a feeling that this is possibly a Romani name. I haven't come across it before, but it's similar to a lot of other Romani names I've encountered - very unusual names which often get passed around within a small group of connected families. There are two other people called Spizenny in the UK birth records who have the surname
Smith, which was a very common Romani surname, and they were both born in Herefordshire. Do you know anything about her?