Thank you for your query.
Your daughter must have received at least 3 doses of her DTP and Hib immunizations in the first year and booster at 18 months of age. If she did not have any discoloration with the initial immunizations then it is very unlikely that the discoloration and hair growth is due to the vaccine
. It must be a coincidence that your daughter must be developing a hairy nevus
at that site. You may get this cross checked with your doctor and in my opinion there is nothing to worry about it.
I hope I have answered your query to your satisfaction.
Wishing your daughter all the best.