I do my brows like that sometimes...(she's so freaking adorable, BTW...) and usually what I do is use Brun shadow and start out by just filling in my brows nice and dark (I use a hand mirror for this part), then stand back and look into my bathroom mirror to kind of sculpt them...making sure there's no sharp corners (on the underside or top...you want everything to gradually arch and taper), and getting them fairly even. Follow up with some clear brow set, and voila!
I don't worry about them looking exactly the same, as long as they don't look totally whacko, you're fine. I read on here (I don't remember who said it, sorry!), in a FOTD, or Tut, a girl who said something about her eyebrows being sisters, not twins. She had a great point, and I took this to heart, and found doing my brows to be much less stressful, and they still look great, even if they don't look like carbon copies of each other.
HTH!