I would suggest something simple: feed her more at night. First, give her a good dish of solid food rice mixed with a veggie in the evening. Then nursing is nothing more than the remaining "fill-up" to wash down the solid, rather than the full meal she wants through breastmilk alone. You may need to try to push back the last feeding. Not all babies do the 8pm-6am sleep thing. My son certainly didn't. Looking back into my baby journal, I wrote at around 4 1/2 months: "He's finally sleeping through the night--11pm-6am!" 7 hours straight with a non-sleeper baby was wonderful! He gradually added another hour, then another until he did 9 hours.
I agree the pacifier is a good idea to try. Don't believe this "nipple confusion" the adamant breastfeeding moms say. Babies are pretty darn adaptable. If all she needs is comfort, then when she fusses, let her fuss a little, see if she goes back to sleep (give her at least 5 minutes), then put the pacifer in. Teaching a child how to get themselves to sleep is probably the nicest thing we can do for our young children and selves. Just look on here at how many moms are desperately begging for help on that now that they have toddlers with sleep issues.
To do that, start establishing a routine, even if it's at 9 or 10 at night. Some food, a little bath, a little lavender lotion, then breastfeed. Turn on some music or get a crib toy that plays music (it'll also help distract her when she's upset. I'd push our aquarium and tiptoe away on those awake nights, and my son would be asleep again before the toy turned off). If she requires a pacifer, then go ahead and give it to her. At her age, you could even try a new sleep position. I've known a few people whose babies just would NOT sleep flat on their back, and needed to be side or tummy sleepers. They changed the position, then their sleep problems were gone.
I hope that just a few minor tweaks is all you'll need to get her sleeping. Btw-yes, that teething time can last months and make her wake up fussy. If you feel little hard bumps on her gum (the bottom two almost always are the first ones), or see a small red bump in that area, try a bit of ambesol or tylenol at night. Though again, the pacifer might help there, too.