Is slipstream Starscream's sister?

Excuse me, I was wondering if you could clarify something for me regarding the Transformers universe. In the context of the lore and the various iterations of the franchise, is Slipstream indeed presented as Starscream's sister? Or is this a fan-conceived theory that has gained traction within the community? I'm trying to get a definitive answer for a project I'm working on, so any clarification would be greatly appreciated. Thank you for your time.