I'm sure you may feel your breastmilk has diminished, but I assure you - with constant suckling it will quickly return to normal even if things had changed a bit. 6 months is around the time of the second growth spurt - - she will feed and feed and feed and seem unsatisfied - but that is only to get your body to up the milk production.
Keeping hydrated, eating healthy foods (especially oatmeal) will go a long way. If you STILL feel your aren't producing enough, the supplement combination of Fenugreek and Blessed Thistle will increase most womens milk production in under 4 days.
I'm sure you are doing fine... and keep your stockpile of frozen milk for emergencies!! Goodness knows you can't pump much now (which is also normal, most women can't pump past 4 months).