网络女友, does that mean you are "dating" the girl but you two have never met?!

internet girlfriend = girlfriend [met] on the internet = [在] 互聯網上 [認識] 的女朋友 (traditional) = [在] 互联网上 [认识] 的女朋友 (simplified) If this is a friend of female gender and you prefer to particularly clarify it, you may use 女性朋友 to express the term as "a female friend". If this is just a friend that you met on internet, then you may simply use 網友 / 网友 to express him/her as "an internet friend". --- 祝　是日安好。/ Good day.

在网络上相识且双方都陷入爱恋的成为你的网络女友，一般性的只是在网上认识的一般网友的是女网友

you can say 互联网女朋友，but 网络女友 i think it is better ,more native