"Sleeping through the night", for a baby, means sleeping at least 6 hours straight. Your baby seems to do that. You are lucky. It's normal.
Also keep in mind that as they develop and grow, babies go through growth spurts in which they get hungrier. ALSO, as they develop physically AND cognitively, their abilities & awareness increases...as they acquire more skills they actually may sit-up, stand up in bed and not necessarily know how to get themselves back to a "sleeping position" by themselves. This wakes them. It's developmental based.
Yes, it's important to keep to a sleep routine, same nap/bed times, same place, same sequence, same everything. When my son goes through these developmental and growth spurt based sleep interruptions... I just KEEP to his SAME sleep routines, everyday. I do not diverge from it. Then, as the "phase" passes, he goes back to his regular sleep pattern. My son, who is 19 months old now, goes to bed at 8:00 and wakes up in the morning at 7:00 a.m. He also naps 2 times a day, morning at 9:00a.m., and in the afternoon at about 2:00p.m. He naps for 2 hours each, and still sleeps at night fine. I've had this routine for him since he was a baby. And I always put him to nap and bed in his crib while he is still awake.
Your daughter may just be hungry and need to feed more if she is going through a growth spurt. Keep in mind that they are changing so much each month. This can really affect their sleep habits. As adults, we too have had different sleep routines and habits all our lives as well, right? But, the key is consistency with a baby. They need routine and "knowing" what will come next. My son knows his routine he will now even "tell" me when it is his nap time and take my hand and lead me to his crib, and he gets tired at these times. I never have to force him. This is the benefit of keeping them to a routine.
If your girl is just getting up one time during the night for a feeding, you are lucky. Feed her. They are growing and need this sometimes. She is only 8 months old. Babies wake up. Each child is different... my eldest child did not sleep through the night until she was about 3-4 years old. Again, lots of children do this too. So... I would not expect a baby to sleep all night without waking up. But, you can teach them to self-soothe. For example, My boy has a stuffed toy that he loves to sleep with, and a pacifier. That is the only way he will sleep consistently. Also, if he does make noises or wakes up, I don't swoop in right away unless he is having a night-terror or something out of the ordinary. I "know" his sounds and when I need to help him. I let him go back to sleep by himself if it is ordinary wakings, and he does. He's learned to do that.
Every child is different, but a consistent sleep routine helps. I know it's not easy having lack of sleep for a Mom, but well... our babes grow up so fast, and this phase will pass. Good luck,