Can the ladies worship the shivling by touching?

Of course! God is not discriminatory to males and females. If women are worried that the ling is a phallus and hence must not be touched, then they must also remember that the base of the lingam is the yoni or vulva--the shivlinga is essentially the cosmic union of the male and female energy that brings about the creation of the universe. Just keep a pure heart and pray with devotion--Shiva will bless you.