Sally, Like wing said, give it a go with moving her to a safe location and give her a couple of fake eggs to start, then just replace them with 5 or 6 eggs she can hatch out. I would choose a floor level location with at least 2 open sides or a box which is very oversized. With her sight deficit she will need to look at things from more than 1 position to figure out her best way to move.
2 weeks is not too long... the two broodies I just posted about were setting for about 3 weeks before I got them eggs and they did just fine. If she is placed in a quiet location you can just give her a dish of 'treat' each morning or evening to make sure is getting plenty of protein and nutrients. Our favorite for the broodies is chick starter mixed with either scrambled egg or cooked fish, meal worms, raisins or rinsed corn can be added in small amounts once in a while to keep it interesting for her. We also switch the broody's main food dispenser over to chick starter since the don't need the calcium when they aren't laying.
As far as her finding food and water... she should have no trouble with it, you can add a 'night light' if you want (literally just a plug in night light or a small string of the mini Christmas lights) after the chicks are hatched. We place a chick waterer right in the corner of the nest for our broodies but for yours you will have to make sure it is secured so she doesn't bump it by accident. Continue her daily treat feeding for the first 3 or 4 days after the chicks are hatched, it will allow her to show them how to eat very early without even having to be up walking around, they will also be a bit stronger and faster when they do finally get out and around.
You should see how often our broodies accidently send a chick tumbling when they are scratching for goodies... the babies just get up and run back to see what they missed! Allow mama and babies to stay in the secure area for at least 2 or 3 days so the little ones are better at listening to mama. I give them finch seed to scratch for the first few days, it is tiny and a good way for them to learn to scratch.