I went for Maureen Connolly as she could have won heaps of slams had her career not been curtailed by a riding accident. Graf with her 24 slams and Evert with 18 (and btw her 125 match winning streak on clay) are the other worthy contenders in this group and I hope they both also get through.
Shirley Fry won each of the 4 slams in the fifties, doing the much vaunted career slam. She won 17 slams across the singles and doubles and mixed spectrum. She was also world number one in the fifties.