My daughter got her first period on 9/28. she is 12 years old. since the 28th she has had a light flow that stops for a day or 2, then starts again.

Be patient: Young women will often not ovulate or do so on an irregular basis in the first months after menarch. That first cycle may have been driven by estrogen alone,and be odd.The pattern of timing and flow can be unpredictable.After the first year the timing and pattern should be predictable.

Her hormones are in: .. flux for somewhat in puberty, so hang on for the ride. Irregular periods and spotting could mean you may have some hormonal imbalance that could be affected by many different factors, including age (if approaching menopause?), nutrition, illness, exercise (or lack of it), body girth, psychological well-being, stress, season, or simple fluctuations of other related hormones (e.g. thyroid)