My 7 year has just got a red stain on her face

I noticed that my 7 year old daughter has a small dark red stain under her eye.  I took her to the Dr. and he said she has a port wine stain, but she had never had this stain before.  To my knowledge portwines are birthmarks.  She is very insecure about it and want to apply makeup to hide it.  Well today, I noticed on the other side of her face, under her eye is she getting a large brown stain.  Why is this happening to her beautiful baby skin?  I hate for her to notice these thing at such a young age, but she does!  What is this and is there treatment?  Should I get a second opinion?