Well 1.5 oz is close to 2 she should be fine. You can't force baby to over eat or she'll throw up or gain to much. She'll want more soon. My son was like that and by 2 weeks old he wanted 4oz
That sounds normal to me, their tummys are so small and she's feeding at every feed without being hungry inbetween (not screaming to fed again 30mins later), but if worried tell your dr. He'll weigh her at the appointment and let you know that way if she's not getting enough.
That's during the day. At night she is wide awake from midnight to about 3 or 4 am. And after that gets up every hour or so just to eat .5-1oz...
It could be. I would wait and see at the appointment if there has been any weight gain.