It kind of seems like you can’t have one without the other. I think it goes back to the fact that she has consistent biblical and mythical references. Frankenstein is a modern Prometheus. Prometheus stole fire from the gods and was then chained to a rock to have his liver eaten by an eagle every day for the rest of eternity. He “stole” things that he was never meant to understand. It’s both the manner and the development itself. She sees Frankenstein (as far as I can tell in the book) as messing with things he was never meant to understand in ways that he never should. Prometheus’s “fire” wasn’t wrong. It just was never meant to be his, just as Frankenstein’s “monster” isn’t an actual monster, but just something that was never actually meant to be in the world. The issue Shelley has isn’t with the concept of the technology, but with the fact that it isn’t something we were meant to have, and with the idea that we are going about finding it the wrong way.
I also think the abandonment issue goes back to the death of her daughter. Its reasonable that any mother that loses a child at birth would carry a certain amount of blame, regardless of it actually being their fault or not. Shelley probably carried guilt about the loss of an innocent, and is now reflecting that back through Frankenstein’s mistreatment and misuse of the gift of life.