Here is a simple explanation of the spots that I found in case you are wondering exactly what I am talking about. Chloe now has three spots that are 0.5 cm. The spots are located on the right side of her chin, her right forearm, and now on her right flank (between her ribs and hip). We have pictures of the ones on her arm and chin and they are very tiny. They just look like birthmarks.
Cafe au lait spots are flat, sharply demarcated, evenly pigmented flat spots that are more or less oval, with the long axis situated along a cutaneous (skin) nerve tract. They are light to medium brown, as reflected by the name - which of course means "coffee with milk" in French. They are usually present at birth, but may arise later in the first few years of life. They are much more common in black infants.
To have a few such spots is totally normal. However, more than six such spots of greater than 1.5 mm in diameter prepubertal or greater than 5 mm in diameter postpubertal children will get the doctor's attention, because they are then essentially diagnostic of neurofibromatosis (although other features are required to make the diagnosis and some individuals may have multiple spots without having the disease - a trait that is itself inherited).