User blog comment:Skeith9/Heroic Spirits Speculation/@comment-25951993-20160409160031/@comment-175.139.97.100-20160429041004

While I can't speak for the uncles cousins, half-brothers and nephews, I can however say that Artoria definately doesn't have any other children in the Nasuverse, aside from Mordred.

Not to say that she couldn't as it has been highlighted Merlin did transform her into a pseudo-male, for the sole purpose of producing an hire. The problem is, I think that Artoria found this very unnatural and messed up the moment she met Mordred. In fact I think I heard one of the type-moon big three saying that Artoria was already turned back into a girl right after Mordred was born.