Can someone help ?!?

Help me!!! I am at a loss so I am trying to stay off the internet my daughter is almost 2 weeks now and if I feed her every 2/3 hours she will spit up a lot ( I know it may seem a lot but it really isn’t ) but I don’t want her constantly spitting up getting fed every 2/3 hours so I decided myself to move it to 3/4 hours and that has helped SO much she at her birth weight, pees and poops a lot, she feeds for 20 min +. I mentioned it to her doctor and she didn’t say NOT to do it so I’m guessing that’s ok?? But she was a preemie born at 34 weeks + some days and her doctor wants her to gain an ounce every day until she sees her next week.. is this okay?? I’m looking for something to help out a little bit this is my second but with my first he woke up every 2-3 hours to eat and she did also but she will sleep 3-4 hours during the night until she gets hungry.. any advice is helpful.