I've started a new character with a few hours put into her and she's up to level 3, but I realized i was leveling her up in a direction i didn't want to go (putting points into melee/big guns when i'd rather be the stealthy sort). Is there any way though cheats/mods to basically reset the points/perks i've already given her so i can re-specialize her without having to start a new game?

I assume you're playing on the PC - if you're on PS3 or XBox 360, you're stuck unless you create a new character.

You can use the player.modav command in the console (on PC) to raise and lower your stats. For example, to lower your Big Guns skill by 10 and raise your Sneak skill by 10, you would do the following;

Open the console.
Type player.modav bigguns -10 then press Enter.
Type player.modav sneak 10 then press Enter.
Close the console.

You can use the player.removeperk command to take away a perk, and the player.addperk command to add a perk.

You can manipulate pretty much any of your stats like this. This http://fallout.wikia.com/wiki/Console_commands summarizes the available commands and how to use them.

One thing you can do in the future, to avoid having to go through the whole childhood in the vault sequence if you decide you want to make major changes to your character, is to make a save right before you leave Vault 101. You get the option to make any changes at all that you want to your character prior to leaving the vault.

level 3 is pretty close to the beginning of the game, just start over
its always good to have a save or two at various early levels. right before you leave the vault is a good place to make a save.

THIS