We shouldn't always jump to the conclusion when a young person dies that it was a result of drugs or any kind of substance abuse. The Geldof family deserves more. We simply don't know what medical issues, if any that Peaches Geldof dealt with. We should wait before we come to any conclusions.
Some people are questioning rather it could have been a drug over dose. Others are asking this benign question, rather it could be a natural death. Personally, I don't think it's any of our business at all. Given that natural deaths occur all the time, I think this is the best assumption.
An inconclusive autopsy almost entirely rules out the chances that she died of natural causes. Furthermore, the typical 20-something does not randomly drop dead. Geldof had a messy past of drug problems and many recently feared she had an eating disorder of some kind due to her thin, unhealthy appearance. It wouldn't be shocking if the toxicology report showed that she died of some sort of substance overdose. It would be sad, but it certainly would not be shocking.
No, it is not likely that Peaces Geldof died of natural causes, because she was very young. People who die that young usually do not die of natural causes. She was connected to the entertainment industry, and the industry is known for its drug use. She likely got messed up in the wrong things.