Heart Murmur

Hi ladies. My 2 year old went for her checkup today, and the ped said she is hearing what she believes is just an “innocent” murmur but wants us to go to a specialist just in case. My daughter had never had an issue before and she told me to not worry… but just curious how common this is or if you’ve gone through it? I read online it is really common and our doctor is always super cautious and very thorough, which is a good and bad thing!