I can only dream about such a lady. I wonder what is the normal cut off range for the ladies to where they can no longer successfully deep throat. I've seen some impressive things, but only in porn.
My opinion and observation on this is until a woman get skilled at doing it she may want to avoid the big boys that's like 8 inches or more because you would pretty much have to Deep throat all 8,9,10 inches the whole time just to get to the balls.
Maybe ladies practicing on a small dildo until your skills are really good will be the way to go until you ready for the hung boys. Just my 2 cent