How many breaths a minute is normal for a 3 month old?

my baby has been congested for about a week now. i have the humidifier on and she is sleeping on her back but i cant really see her breath unless i look really close. im wondering what is normal for a baby this young, i counted and she has about 20 breaths a minute. is this normal? my son is 2 and his is around 20 also. is that normal even though they are different ages?