no she isn't too young to start teeting. my son started teething at 12wks!!! yep that's right 3mos. he cut his first two teeth at 4.5mos. every baby is different.
i used Hyland's Teething Tablets, they are homeopathic and work well. they have no side effects. when he was teething badly i would use the teething tablets in conjunction with tylenol or motrin. you can also get some teething rings you can freeze. first years puts out a rattle shaped in a star, when the baby bites on a tip of the star it vibrates, thus massaging their gums.
one more thing ORAJEL is very temporary relief, maybe 20-30mins. it is also known for toughening the baby's gums, that results in making the teething process LONGER!!!