From what I understand this is not necessarily uncommon in children. My son had one that could be heard occasionally, from about the age of 3 to about 10. We went into a cardiologist and did an EEG, and it wasn't happening at that time. According to my Pediatrician and the Cardiologist this is an issue that can happen to younger children as they grow, and in those cases it will stop. I hope that is the case for your daughter. I remember how scared I was when they sent us to the Cardiologist. I asked questions about what to listen for, and how he should look: coloring, chest and stomach contractions during breathing, how they hold themselves if it creates pain, etc. Every now and then he would say that his heart "felt funny" as if it was skipping a beat. That happened off and on, but we wouldn't freak out unless it kept up. It usually went as fast as it came.
I would say just ask the questions about growth, looks, and feelings. Keep it simple. You don't want to overdo the information at first. If you ask questions about down the road issues, it will keep you up at night wondering "what if". Stick to the here and now. If the doctor thinks that more testing is necessary (beyond an EEG and basic testing) ask about those and what that will tell you. Then when you get those results ask about what will need to be done then. You want to stay as calm as possible around your baby, or she will pick up on the worry...and that helps neither of you.
Don't leave with out "marching orders". Even if it is just to keep and eye out for certain behaviors or physical traits. Make a follow up appointment with either the Cardio or the Peds doc so that you have that comfort of knowing that there is another time they will hear her heart. Something might have changed in that time, and you will feel better knowing that you have that next step already in place.
I am praying that you only have to deal with a little growing (like I did). Good luck, take a deep breath, and relax (easier said than done). It will be OK.