Pattern should fit 4 weeks to about 5 months though it will be a touch large on the 4 week olds. Next size up can be achieved by using a larger needle and increasing the length of the foot slightly.
28.06.10 a larger size again has been added for about 12-15 months. Length is easily customizable so should fit a larger size range.

If you wish to knit this for sale I give permission, but would appreciate it if you put a designer tagline on the pricetag.

For EU purchasers, I have requested this be uploaded on Loveknitting.com as well, but it’s not yet showing as accepted. If you’d like to purchase in the meantime message me with your email and I’ll send you my Paypal details so I can gift you the pattern via Ravelry; this is a temporary workaround until Loveknitting deals with the backlog.