Babysitting a puppy - advice?

As the title says, I'm babysitting a 2 month old puppy for my neighbour. Got her today, and have her until next weekend. Not sure of the breed, but looks like a very small Rat Terrier with perhaps a little beagle mixed in. Real nice quirky personality already. Just wish she didn't have to pee every hour or so! She makes these cute whining noises, at which point you have maybe 30 seconds to grab her and get her out the door. Otherwise, you have a little puddle to mop up. Luckily so far, all accidents have been on linoleum or tile, but I'm a little concerned about my bedroom wall-to-wall carpeting.

Question: would I be considered a horrible person if I left the puppy overnight in the kitchen with the door closed? I have made a "bed" for her out of a cut open box and laid a large soft cloth folded over several times in it. She seems to like it, and is already going there on her own for naps. She can easily get in and out by herself. So she would have a comfy bed to sleep in, food and water, a totally safe environment with no electrical cords to chew, and I'd have peace of mind. The window would be tilted open for fresh air (double hung and above the counter so she can't get out). I realise she probably will whine at first being left alone, but hopefully she would settle down after a while. But I'm really not sure. See, I'm a cat person and don't have much experience with puppies. Not to say I don't like dogs, just that they are higher maintenance than cats so Mom always said no. Don't have any pets at the moment, unless husbands count

Any opinions?