It can be quite hard to tell when they are this young. My "guess" would be a female. In young budgies both may have the purplish colored cere but the female will usually have a bluish tint and have paler to white rings right around the nostril. The males will usually have more of a pinkish tint around the nostril or have no real lightened place around the nostril tint and not have the lighte or whitish rings around the nostrils. So even though I am not 100% certain I would guess a female since it does have more of the bluish and the lighter color. As they age of course the females will turn the more pinkish/brownish and the males will be more of a bright blue with no purplish tint.