Singulair and migraine headaches

My daughter has been on Singulair since February of this year. She takes it for her severe allergies. She had a nasal cauterization two years ago and last year noticed she was experiencing swelling again in her nasal passages. Singulair helped with the swelling and stuffiness. However, she also started having an increase in her migraine headaches. (I've just read that Singulair is being prescribed to "help" with migraines.) Also, during the last few months, she's had a general "not well" feeling. She's also been experiencing flushing of her face, arms, and hands. She is also hot all the time.
The only information I could find on the side effects were a rash. She doesn't itch.
We had decided last night for her to go off Singulair, and after reading all the problems others have experienced, I know we're making the right decision.