My 6 month is old cutting her first tooth. at what point should i take her to the doctor?

No need: Take her if you're concerned about any abnormality. Otherwise, teething is a natural, usually uncomfortable, experience for your baby. It just requires management of symptoms, but no treatment. Use chilled teethers. Freeze milk into a pacifier. Use Acetaminophen as directed by your pediatrician, to mange fever.

Teething: This is a normal time for this to occur. No need to see the dentist unless you feel there is something abnormal. When your child is closer to having all their teeth then start visiting the dentist regularly. I have parents bring children with them to their appt and get the child comfortable in the chair and with us then eventually begin cleaning and exams.