I wouldn't worry about it. As long as she is eating a healthy amount, it really shouldn't matter when she eats it and for how long. I find that tiels tend to nibble throughout the day whereas budgies gorge themselves just once and are done for the day It kind of reflects my eating habits LOL. I suppose it has to do with the flock situation (singular birds tend to take their time eating while birds in large flocks tend to compete to eat), too.