Multiple perpetrators: who is guilty?

You didn’t specify a country. There are some principles, but different countries will not agree on details.

We assume that both Alice and Charlie did what they did intentionally, but did not intend to kill Bob. For Alice, she should have foreseen that when there is a fire, someone might die. Fires kill people. For Charlie, it’s less clear. He should have foreseen that a body slam moving someone through a door might be lethal with some bad luck. But most likely it wasn’t foreseeable that there might be a fire killing Bob, so Charlie wouldn’t have committed murder.

Charlie may or may not be guilty of murder or of attempted murder. It depends upon his intent and knowledge, which the question doesn't flesh out sufficiently to evaluate. Why did Charlie bodyslam Bob? The reason matters a lot. Did Charlie know that the building was on fire? Was Charlie trying to kill Bob? Was the thing that Bob knocked his head upon an intended result of the bodyslam, or an intervening cause? Did Charlie's initially less culpable act and his knowledge combine to create a duty to rescue and what offense (probably not murder) would it be if a death resulted from a failure to rescue?

Alice is likely to be guilty of murder, but on a felony-murder theory, rather than on a transferred intent theory. In most, but not all, states if you are in the process of committing one of an enumerated list of specific felonies that pose a high risk of serious injury or death, such as arson, you are guilty of murder in the event that anyone (even a co-conspirator) dies as a result of your felonious course of conduct, whether or not you intended that a death result.

Alice might have been able to purge her felony-murder liability if she had tried to put out the fire and save Bob once she realized that he was in danger, under the exception to felony-murder for renunciation of a course of felonious conduct, but she didn't even try.

The doctrine of transferred intent in a murder case usually applies when you intent to kill one person and instead end up killing someone else. But, Alice didn't intend to kill anyway, so this doctrine does not apply.

Alice's best defense would be that the death was a result of the attack by Charlie, rather than by the fire, which she would merely have to establish a reasonable doubt regarding. But, ultimately that would be a weak defense for her.