Maybe so but that is not where get_avatar() is defined.
As I told you previously, you have not posted the code for that. There is little point trying to point me to the same source that I have already looked at. I've already used 'Find' in Notepad++ and get_avatar is only found once in that code - line 378. It is not found anywhere else which means that get_avatar() is defined elsewhere.
You did say this was a wordpress site so maybe its in a wordpress file you've tinkered with.