Hey I went through the same stuff with my boy, he's one now and sleeps through the night like the perfect little cherub he is. Now since she is eight months old it's time to be "TOUGH MUMMY" LOL! First, look for every single thing that could possibly be wrong.
1. Teething, very good possibility as they start teething like crazy around this time and it acts up at night in that case try teething tablets, tylenol, and frozen things
2. you're right, at the time they start crawling they get so excited about their accomplishments that they do have sleep trouble
3.Gas, massage, loosening their diapers and putting them on their bellies (they wont suffocate dont worry) will all help with that.
If you have tried that to no avail then it is time for Mommy to say good night and leave baby to go to sleep on their own. Guaranteed they will scream their heads off for hours but they WILL figure it out. And believe me, it works. Lastly, she's old enough that she doesn't need to breastfeed at night so when she wakes up to nurse just put her back to bed and do the crying it out. If she continues to cry constantly just go back in her room and lay her down (cause she'll probably be standing up) and tell her "night night time" Believe it's hard but it works so well in the long run. And last but not least NEVER put her to bed asleep. But I think you already knew that. Anyways GOOD LUCK!