Gail Simone (and others) in WiR (lby3-dot-com-slash-wir) compiled a list of bad things that happened to female characters in superhero comics, but she did not use the term "fridging" there, let alone define the term. That only happened later. Note that on

I didn’t even know that but you are right.

Gail Simone, for the better, was making an observation about the treatment of female characters in order to make a larger point about sexism within the industry/medium and from there hopefully trying to address it.

She essentially took individual examples and put them together to paint the full picture.

She wasn’t laying out a criteria for acceptable or unacceptable writing.

She even had on that site a section for people to give their own thoughts and hosted a ‘counterargument’ of sorts which made a case for certain examples where the treatment of such characters was justifiable, citing Gwen and Jean among them. 

This doesn’t mean Simone AGREES but my point is she wasn’t outright saying ‘X, Y and Z = fridging and therefore sexism’. She was opening up a long overdue conversation we are still having.

At the same time I’ve noted at least one example in Simone’s own work which you might argue would either count as a fridging, something close to it or something which if it had been done by another writer before Simone made the original list and she’d been aware of it more than likely would’ve justified it’s inclusion on the list. I’m talking about Sandy in her Deadpool run, the first six issues where she is in an abusive relationship, gets beaten up and this then pushes Taskmaster into seeking vengeance on her behalf.

Now I’m not saying this invalidates anything she says. I’m just saying her efforts were never to lay down the law on what is acceptable and what isn’t or when it is acceptable and when it isn’t. 

She doesn’t have word of God authority to dictate when something is and is not a fridigng nor when that is okay and not okay.