I don't remember the exact age, but mine started spitting up at a weeks old age, just out of the blue. My doctor tried to tell me that it was acid reflux and he required a prescription. Other people kept saying, "Oh, that's what babies do. Just keep lots of burp cloths around." They didn't listen to me when I said, "Not my baby. My baby does NOT spit up, so this is something else." He was breastfed but not exclusively. (He had a little formula when we ran out of milk for the day.) It didn't help to keep him sitting upright after feeding or to sit him up after nursing. We had to switch his formula to soy from dairy. Gerber worked better for him than Similac. I had to figure out some stuff about the way that I was nursing him. Once we got that together, he stopped spitting up, just as suddenly as he had started. No, he didn't seem to be miserable, but even that bit of discomfort wasn't all right with me if I could stop it. That's what we want for our children, right?
It sounds like your baby might very well be "fine", and I'm not looking to make you worry. I just don't like the dismissive tone that others use--"Oh, that's what babies do." That tone keeps you from trusting your gut and getting to know YOUR baby for yourself in a way that helps you to pick up on the tiny things that might seem "normal" to many others.
Watch your baby. Pay attention to those little things. If the spitting up persists, continue talking about it and do some research. Do what makes you feel comfortable, what helps you to feel like you have a good understanding of what's happening with your little girl. Even if your baby is a designated spitter, there is reason for it. Even if you are okay with letting her spit a little as long as she's still looking and behaving like a healthy baby (and that IS okay), don't do it because other people convinced you that it's "normal". Do it because you know your kid and your soul tells you that she is fine. Don't just settle on the word of someone who doesn't know YOUR baby and doesn't look into your baby's eyes all day every day. Become an expert on your baby; don't give that power over to the doctor or to others with experience. The doctor is your partner in your child's care, not the authority. And no one else has experience with YOUR baby.
Oh, and congratulations on the new beauty in your life!!