Yes, correct. It's better in the federal system where there are sentencing guidelines. In most state courts, there are only minimums and maximums, and so long as the judge is within that range, while the prosecution could theoretically appeal, there wouldn't be any good grounds. In federal court, however, any judge letting a defendant off with no time for that many felonies is going to get reversed.
No, Trump isn't going to get no jail time here. If convicted and not let out on appeal, he's going to die in prison. While I'm unfamiliar with the sentencing guidelines, I can't see him getting less than 10 years. I think some people are still not getting how serious these charges are.
The judge could in theory Rule 29 it, which is like a JNOV (judgment notwithstanding of verdict) in state court. But it's a rarely used and extreme remedy. In this case, the evidence is so strong that were she to do that, I think she'd have reason to fear being thrown off the bench for misconduct.
If she wants to help Trump, her best bet is to let him delay the trial until after the election.