Parakeet molting age?

[Bird Mom]

So about 2 months ago I got two parakeets from petco. They had said they had just came in and were between 4-5 months old. I got a male and female (in hopes to breed once they are mature). Well, I notice one of them has started molting. When I read online it says that parakeets under 4 months old have a molt and full stripes from the cere down the back of their neck. The male (Tramp) has full stripes, a purplish cere with blue rings around the nostrils. But he also has started getting a grey iris. She has a white cere with pale blue around the edges and appears to be starting to get a white iris ring.
He is a blue grey wing mutation and she is an albino.
Does this mean one of them could be just turning 4 months old?
(I can't tell which birds molting yet as I don't see any pin feathers since it just started today)

[spiritbird]

Four months is quite young to molt new feathers. In my experience with budgies they were over 6 months before a molt.

[LunaLovebird]

Parakeets start moulting very young. 4 months might even be a bit old. I think they usually start around 12 weeks.

[Bird Mom]

Hmm.. I'm just confused as to what age these birds might be. I thought they were now atleast 6-7 months old but I didn't find anything online about a 6 month molt just that they have a molt at 3-4 months old then once a year. I'm just concerned if they are younger than I was told. They had just arrived at the store when I got them.

[spiritbird]

If they will show you the shipping papers that come with the birds you might find the age. Am so the information on leg band would have year of hatch.

[Bird Mom]

They gave me a documentation of purchase which tells me what vet they went to for a check up but it doesn't say hatch date. I know they are young and definitely born 2015 but I need to know the month. Their leg bands are different colors from eachother. He has full stripes though, like they start right as the top of his cere ends and go all the way down the back of the neck. She is albino so it's harder to tell.