Pubic hair (pubarche) is usually the second noticeable change of puberty, and on average begins between age 10 and 12.

You get your period and you get hair down there too

Different parts of puberty have different names:

Pubarche is the name for attaining pubic hair.

Thelarche is the name for breast growth.

Adrenarche is the name for a time of increased hormone production.

Menarche is the name for first period.

Spermarche is the name for first ejaculation.

Gonadarche is the name for when the testicles and ovaries enlarge.

The age of 7 is too early. If pubic hair is visible at that age, then it could indicate a problem. Some brain disorders may cause early onset of puberty as well as certain tumors that produce androgens. Normal pubarche happens shortly after the genitals start to grow which has been consistently reported as early as age 10, though many seem to think that is a bit young. Any earlier than 9.5 is a possible indication of something wrong. Though keep in mind genetics and other factors also contribute to a child's growth and currently not all factors can be predicted with certain accuracy.