There is no link yet detected between early onset of menarche and better nutrition. There is, however, a connection between early onset and body weight. As stated in this abstract of a Danish medical study:

Late menarche was associated with underweight . . . , and early menarche with excess weight . . . .

Helm, P., K. Munster, and L. Schmidt. "Recalled menarche in relation to infertility and adult weight and height". Acta Obstet Gynecol Scand. 1995 Oct;74(9):718-22. Abstracted and indexed in PubMed. National Library of Medicine. Online. Accessed 05 August 2003.

Similarly, anorexia is associated with delayed menarche, as is zealous pursuit of strenuous athletic activity.

One of the medical complications of anorexia is loss of menstruation. Extreme loss of body fat can cause a woman’s body to stop producing adequate levels of estrogen, which is essential to menstruation and bone growth.

Jaraus, Joel P. "Dying to Be Thin: An Opionion on Anorexia". East Central Minnesota Post Review, 28 February 2001. Online. Accessed 05 august 2003.

Self selection for gymnastics and training may result in a decreased intensity of growth, delayed onset of the symptoms of sexual maturation and altered rhythm of the consecutive stages of development (Ziemilska, 1985). The often found delay in menarche has been attributed to: net caloric deficit with exercise over time, low weight to height ratio, critical body weight, and the composition and altered hormonal levels.

Richards, Joanne. "Talent Identification in Elite Gymnasts: Why Body Size Is So Important." Edinburgh, UK: Moray House School of Education. Online. Accessed 05 August 2003.

Body fat to height ratio is the trigger, not vitamins or minerals, or muscle mass.

Regards--
Mary Anne