No worries about disturbing me. I think you would want to create an integer variable that you connect to Active Child Index and then you should be able to access that variable in your level blueprint by first getting the player character, getting that character’s mesh, getting that mesh’s anim instance, cast to your particular animBP and from there, setting your variable. I know that sounds confusing; so I made a quick example below:
All that said, that may not be the best way to achieve what you are trying, but I think it should work. 
Good luck!