I'm not sure how someone else helping you to create account has anything to do with being reported for alleged misconduct. Unless, you're equating misconduct with having someone create an account for you?

For one, why would anyone need to know that about you and the account? Sounds like extraneous information that wouldn't come up in regular conversation.

Second, I wouldn't listen to anyone on this platform making threats about anything or anyone. It's a video game platform. Why take anything on it so seriously?

引用自 MissQubY：

I was threatened with being reported for alleged misconduct.

Is it possible to get banned if one of your relatives created your Steam account for you?

Examples of such a scenario:

Mental limitations that make it difficult or impossible for you to do this yourself.
Not having an email address.
Or other reasons that I can't think of right now.

At worse, the account can be locked due to you not being the original owner. But your relative can also provide proof of ownership to have the account unlocked again.