It certainly does sound like she is teething. Have her poos changed consistency or smell and does she have a bit of nappy rash? That was one of the biggest giveaways with my kids when they were about to teethe. Try this advice for some suggestions on how to make it easier on her. 

Im pretty sure that babies teeth their two bottom front teeth before the top.. but anyways.. my son started teething at 3 months.. the drool came like crazy, like a waterfall, he starting bitting/chewing on things, he was kinda cranky but not really, but the night that the first tooth came through i had nooo sleep.. thats when i finally discovered ambesol. it works great. right before he cut through, his gums swelled like crazy he had one HUGE  lump on his gums cuz they were both commin with a vengence.. it took him from the beginning of his 3rd month until he was 4 1/2 months for his first tooth to break through.. i had talked to the nurse cuz i thought that once they start teething they come through quickly.. she said it can take up to 6 months for a baby tooth to actually break through.

I hope this helps a little..

Some babies don't show any signs of teething. I know my daughter got 4 teeth through without showing any signs.  Other babies scream for days on end, have swollen gums, high temperatures, bite everything they can get the mouth around, have runny poos, drool alot, and show any number of other signs.  It sounds like she is teething judging by the drool and the white line on her gums, you might be one of the lucky ones.  Every baby is different, and all the signs of teething are outlined for parents, but not all babies get all signs.  Some get none, some only dribble, some get all of them.  I hope for your sake and hers that she's one of the lucky ones who won't feel the pain as much as some.

I think your bub is definately teething. Her little gums will go up and down until the first tooth is cut and before you know it she will have a mouth full of teeth. Her grumpy, cranky mood is a sign of pain in her mouth.  Apart from medication to relieve the pain, for my kids when they started teething (at four and a half months) I gave them an iceblock to gnaw on.  The zooper dooper types, but did not cut of the end.  I found this useful as after a few minutes the coolness of the ice had more effect than pain relievers and a lot cheaper too.  I normally allowed about 5 minutes for gnawing then popped the iceblock back in the freezer till next time.  I washed the outside wrapper in boiled water first before giving it to them, then repeated the washing before putting it back in the freezer in a glad zip lock bag with baby's name on it.  I hope this helps. 

that is a pretty good sign that she is teething the main signs are grumpy, drooling, biting on things alot, they also get a temperature, and the white line will be the tooth, however they can go up and down. sounds like she is definetly teething to me, rusks are great, and a wet washer for her to chew on is also good, if she is really grizzly and has a temp baby panadol is a life saver and bonjela (just talk to your chemist lady/man about it) hope she has her tooth throw soon. good luck Britt xx