So my supervisor offered me the permanent position. The downfall of it is that it on for a guaranteed 20 hrs a week. But…

So my supervisor offered me the permanent position. The downfall of it is that it on for a guaranteed 20 hrs a week. But she said can schedule me for 40 hrs. It pays $4 more than get now. I just hope I get the 40 hours otherwise I would be getting less even though I make more. She said that I move up to full time when a position comes available. I get benefits and vacation time, 401k and pension.