Sleep or feed

Jenna • We had our first baby girl September 21 2015 👑 she's our world! Now we're expecting baby number 2 in Sep!!
My baby is already back to her birth weight. She normally eats every 3 hours. But she's really had to wake up and feed her sometime. I tried everything changing her, playing with her toes, rubbing her all over and I still get nothing but crazy faces. 
When did you guys let your baby sleep and feed once they were ready? Like if she won't wake up I wanna just let her sleep little longer and try again later... Good idea or bad