Let her "craft" it!
If the player just wants non-magical hide armour, then you can allow it, no problem. Getting "free" non-magical armour is so entirely irrelevant to D&D 4e's economic balance that it really isn't worth worrying about at all. Role-play it, but don't make it cost them more than the item costs. You're basically handing out 6 gold pieces worth of treasure. Hide armour costs 30g and items sell for one fifth their value; so if you really have to track every last gold piece, trim 6gp out of that level's treasure parcel somewhere else, or have the player spend 6gp on crafting supplies.
If the player wants magical hide armour, you can do that too. D&D 4e is extremely "gamist" rather than "simulationist" so it doesn't really care how players get items, it mainly concerns itself with the combat effects of the items dispensed to players. This leaves DM's plenty of room for creativity in terms of dispensing loot, and crafting is certainly one way of doing it.
You're meant to give out a number of magic items equal to the party size minus one, so if you have a party of five, you give out 4 items each level. There's no hard and fast rule that the magic items HAVE to be gained as loot or in dragon hordes: crafting them is perfectly viable.
On the most basic level, you can have that player gain Magical Hide Armour +1, and that be the group's level 2 item, leaving them with three more magic items for the first parcel. But that's kind of boring, right? Alternatively, turn this into some kind of quest: having to obtain some magical materials in order to properly treat the hide in order to impart the magical powers into it. There's nothing better than a side-quest to keep players engaged!