Tooth pain is most commonly when caries reach pulp which is the innermost part of tooth which has nerves and blood vessels . It increases as inflammation of pulp increase and it has no root to escape. So. She can take any painkiller like paracetamol 650mg now for pain relief
Next Steps
consult dentist as soon as possible. and start with right treatment
Health Tips
keep good oral hygiene. ask her to do rinses with warm water and salt. . brush twice and don't eat from that particular side. don't delay visit to dentist.