Babies take a while to figure out how to get to sleep. When they're still really young they need you to help them out. Slowly they get better at doing it by themselves.
In terms of breastfeeding at dawn, because of your hormonal fluctuations during the day this is the time when you're most likely to have the best supply of milk so it could be that your baby is getting her biggest meal at this time of day.
Given you've been resettling her at other times during the night without breastfeeding it sounds like she's able to settle again without a feed so if that dawn feed is difficult to cut out it is probably because she is hungry.
It's one of the most common feeds to persist, and most mothers love that feed because it gives them an extra few hours in bed! When you stop doing that one often your little one will start trying to get up for the day at that hour!!
I found personally that it's much easier to get a sleep settling routine going during the day than at night while you're tired. Try getting some great day sleeps happening and then over time you'll see the night time settle. It sounds like you're little one doesn't get through the sleep cycles very well on her own at the moment, so you can try to work on that during the day for one of her sleeps (if she's still doing 2?)
Hope this helps, make sure you go with your feelings and validate yourself.