Is a point and shoot camera good enough to?

Take photos to be used in 3X6 ft. Banner? My mother is a real estate agent and she wants me to take photos of various houses. I don't know if a 10 megapixel sony cybershot is more than enough or do I need a dslr?

Yes. Get at least 12 MP.

NOPE

The number of pixels is not what is important. The size of the sensor plus pixel count is what will produce an image that can possibly be made into a 3 x 6 foot banner.

Just buying yourself a dSLR will NOT do what is needed. You have to have the skills necessary to use such a camera before you can produce such images for your mom

Here is a sample (in reduced resolution for posting in the internet) that shows what can be done using a digital SLR camera.

The tools needed to take this shot was a tripod and a super wide angle lens (a 12-24 mm set to 12 mm)

This is the lens I use to shoot almost all of the photos I shoot for Realtors.

You must keep in mind that just having the right tools will NOT guarantee that you will get the shots your mom wants.

Today, I would use a Nikon D810 with 14-24 mm lens to shoot such interiors, but if you check the prices of those two tools, you will see that the initial cost may be more than your mom makes on a single commission and you would still have to learn how to use them. The learning curve can take as long as a year if you are starting from scratch, which such a question implies

While I agree with fhotoace for most part, "good enough" is a very subjective term and it really depends on how far away the viewer will be from the image too. If people are going to be within 10 feet it's going to look pixelated and fuzzy, but if the banner is going to be viewed from more than 15 feet, then give it a try. Talk to the printer and his/her advise as I'm sure that they've had a lot of similar requests.
In a perfect world you would use a Nikon D800E or D810 for this situation.