Thanks ladies for the helpful advices / tips. I followed few things you mention above, and by the look of it, seem to work so far and don't think i have low milk supply issues - i need to change her nappy average 3 to 4 hours and all are full and wet nappies. Tried the waking her up approach, seems working so far, but seems as if she is used to the approach so i need to constantly change the ways to wake her up.
I now feed her on each breast approcimately 15-20 min, so in total for each feed is around 45 min to an hour. Before that was shorter as i didn't know that i should wake her up during feeding. now i do, thanks!!