just put it in the fridge and when she wakes up pump a little more. i use to feed every 2 hours sometimes 3 then when she slept through the night i would wait 6 to 8 hours or she would wake me up
after a month old they can sleep all night they will let you know whnen they are hungry i always woke my daughter up after 6 to 8 hours tho to be on the safe side