Hehe, this often happens when you start training them. Do you usually train her in your room? You need to condition her to do her trick elsewhere. Definitely use treats and praise and reward her when she sits in the kitchen. You sort of have to show her that it means the same thing everywhere. Dogs are weird that way, lol. You're right, you've got to love them
If you want to teach her something new, try and teach her to look you in the eye. Hold a treat in your hand and make sure that she sees it. Then move the hand to the spot in front of your eyes. When her eyes follow the treat and focus on your face, say the command (Look, or Focus, or whatever you choose) and then praise and treat her.
Do this a few times and then hold you hand still (out of sight) and say the command again. Wait until she looks you in the eye and when she does, praise and reward her. You need to be patient to let her connect the dots and realize what you want. Otherwise she will get lazy and won't think for herself.
Keep training sessions short and use yummy treats when you are teaching something new. Also, look into clicker training - it makes everything so much easier