If your woman is a eager cocksucker, she loves cock, she needs sperm, you will have a great cocksucker. If she's hesitant, doesn't love cock, dislikes sperm, then she won't be a great cocksucker. Either get a new woman or help her free up the slut persona most women keep suppressed within themselves. Women sho can shunt aside the mainstream moral nonsense regarding sex sometimes become the most willing and enthusiastic sluts.