This image popped up to me during my recent Autumn themed Picarto stream, but I considered it too complicated to tackle during the short time frame of a stream. So I did Cadence instead.
Even after she was reformed Starlight Glimmer was something of an iconoclast. Also willing to question the status quo and the norms of pony society.
So I could see Starlight under certain carefully controlled circumstances being willing to experiment with certain types of necromantic magics. If nothing else out of curiosity. So after carefully reviewing the spell and assembling the necessary components she attempts it.