I'll try to give it all to you here but this is a HUGE subject! First of all, if it's an indoor dog, you can't really start on the grass. Start inside.
Restrict her area. Shut all the doors and keep her in one room with you. Then, set up a gated area about four by four feet (place it near where her doggie door will be). That's her space. Use the pads UNDER newspapers. (There's a good reason for this. If you train her that papers are for potty, then, when you're on vacation or at someone else's home, all you have to do is put down a square of newspaper, say, "Good place," and the dog will immediately GO. It's amazing and worth it. It's not likely that you'll have pads forever or on vacation; that's why you should use newspaper.) Have her bowl of water OFF the newspaper and a home plate (her bed) in the pen.
When you KNOW she's on empty, let her hang out with you (just keep an eye on her!). When you need to leave the room or she's thirsty, walk her over to the pen and pop her inside. After she drinks, point to her bed and say, "Go to bed." Don't walk away until she lies down. When she does, pat her and say, "Good girl. Go to bed." Then walk away.
Stay consistent. Try to catch her peeing on the paper. When she does, turn into a cheerleader and get all excited and say, "Good Girl!!! Good place!" Pat her and act all happy. When she goes even an INCH off the paper (this only applies to an older dog like yours, puppies require more flexibility) say, "NO." Say it, don't yell it, but say it in a deep, unnatural voice. That way, she associates that error with a "stranger". Pick her up and place her squarely on the paper PREFERABLY near a former pee spot and say in a happy voice, "Good place!"
If you are consistent, she'll learn quickly. Be sure to clean up the scene of any accidents or you'll just undermine all your work. The smell will attract her and make her want to pee there again. (Your dog really shouldn't be ON your bed. If you don't let her stay on the floor, you're undermining your own authority and she thinks she's equal to you.)
Now, the poop. Feed her in the morning (place the food and say, "Eat.") and afterwards, immediately take her outside. Take a previously peed (but dry) square of newspaper and lay it on the part of the yard where you want her to go. (Train her to go in ONE spot...it's easier to clean up.) Say, "Good Place!" and wait. If you don't intend to walk her (I think you said you want to have her go out on her own anyway) just stand by her. (Walkers would use a leash.) Wait until she goes and then do the cheerleader thing again. LEAVE ONE PIECE OF POOP. (This makes it easier for her to learn the spot and she'll come back to it later. Clean up the rest, make sure she's on empty and go back inside. Put her in her pen for water or hang out with her in the room. After your family eats (...and doesn't share food! Again, don't undermine your authority!) you feed the dog, say, "Eat," and do the same outdoor routine again.
When you're ready for bed, take her to her pen and tell her, "Go to bed." Point to or pat the home base. Wait until she gets in it and then pat her and praise her saying, "Good girl. Go to bed." Then walk away.
You need to be consistent because you only have two weeks. In two weeks, when the guy installs the door, train her to go through it to go potty. Now, you pick up the paper and put it JUST OUTSIDE THE DOGGIE DOOR. Leave her pen where it is but let the one side of it be the door. Make the pen smaller. The only things in her pen should be her bowl of water and her bed. If you need to, use cut up hot dogs to encourage her to go through the doggie door. Once she's got the doggie door thing figured out,(that means NO ACCIDENTS at night) then move the paper away from the doggie door until it's where you want her to go (the original spot outside).
Wait at least a couple of weeks until you KNOW she's consistent. NO ACCIDENTS while you're at work or at the store. If you're positive that she's got it, THEN you can remove the pen and then just leave her bed near the doggie door along with her bowl.
In the normal course of the day, whenever she gets underfoot or bothersome, tell her, "Go to bed," and walk her over. She should JUMP over there immediately and lie down. If she delays or walks away, then you can't trust her yet. Be careful that you don't take down the pen too soon or you'll never get the training done right.
All of this will go much faster if you keep your commands consistent: Good girl! Good place! Go to bed. NO. Eat. OFF. (That's for OFF furniture.) DOWN. (That's for NOT jumping on people.) Come. Stay.
Simple commands make for a less confused dog and good discipline. (Eventually, I trained my dog with hand signals which is great at dog parks and other public places where your voice can't carry.)
Even after she's got it all down, I still recommend you restrict her area while you're not home by shutting all the doors to this room. It's just smarter!
PS: I just read JjL's response. A crate is a wonderful home plate, just like a bed.