The forehead pain
she is having might be due to problems in her eyes. So, I suggest to get her checked by the oculist.
If you have already checked and the oculist changed her glasses recently; most probably she is having difficulty in adapting to the new glasses. It will be gone by time if this is her case. If no improvement, can consult oculist.
Give her plenty of water, paracetamol
for pain and avoid watching Tv or work in front of computer for too long.
All the best!