You are not the only one having trouble getting that wig on that doll. I've read not all the CAMs have the same head circumference
I know I've had some trouble with a SECOND wig on a SECOND head (same wig type, same head type) my first Vamp fit her wig. Again
It seems like a hit or miss situation. I can't help you make it fit. I just gave up
But I wanted you to know you are not the only one.
LIV wigs are larger. Maybe you could find one of those. Also, I'm a huge fan of CAM wigs. I don't think they are all that bad.......(except for this one combination you've found, and the later wigs. The Cat/Witch and Male CAM wigs ARE horrible.)