Mine is doing the same, when she wakes she barely takes anything and then the next 2 feedings too. Once it gets to the late afternoon, or even evening, that's when she starts taking more including at night every 3-4 hours. I nursed her at midnight, and then , when she woke again at 3 am, I didn't feed her but just tried to put herback to sleep. She was awake for about 30 minutes and then slept till 6 am. I let her nurse, and then she took more at 8:30 upon awakening-not as much as a full feeding but better than before.
She's on a 3.5 EASY schedule right now and is 3 months. Let me know if you have any good ideas of getting them to take more during the day and less at night.