Is a 12x14 cm welt from Menactra Vaccine normal?

My 10 yo daughter had the Menactra Vaccine on her left thigh and within 10 minutes she started having a reaction to the vaccine. Her reaction began with only itchiness; by night fall the injection site had a welt about 1x2 cm; then in the morning the welt was 2x3cm, hot & red. Took her to doc's & they said it's normal. NOW it's 12x14 cm. She's complaining of a headache and very tired. When should be concerned?