Cannot be ruled out Jane but if June was in a fight with anyone it is much more lightly to be Sheila.
You know, were it not for having read rather too many poor scripts, I might be inclined to agree with you! Mike's 'piece' reads exactly like one of them, albeit rehearsed down to the last breath!!
There's the added thing that there have never been any recorded incidents -save JB's claim that she hit one of the boys- of Sheila inflicting physical injury on anyone other than herself.............besides which, blacking someone's eye is, I think, more of a masculine trait. Females would be more likely to slap.