Are my parakeets being aggressive?

i have a female and im not sure what the other is, its about 4 months old and it has a light blue cere, i was told it was a male but at that age its hard to tell and the female is about 6-8months and sometimes the young one will kinda stretch its head out to investigate the female, she'll peck at him and when they r eating the millet spray they will peck at each other real quick. another thing the young one does, is it'll makke this little chattering sound, r these signs of aggression? by the way, i just got them yesterday