Hi Haley,
I've had one of those free e-tools things that you can use for 2 weeks from weight watchers and they have a lot of neat things on it. I think the difference between the two are that if you do weight watchers online, they send you everything you need in order to start the WW program (if you're mom is going, then she would have the same thing I'm guessing) and with e-tools, it just has some handy stuff you might be interested in using, such as recipes and journaling. Try the free trial series for 2 weeks and see what you think and if you think it's worth it and then be sure to cancel out of it (if you want too), before they charge your credit card.
One thing you should know is that what Weight Watchers will charge you much money for by being a part of their exclusive website, you can find free on other websites, such as 3fatchicks and slimfast.com.
I think if you decide to do weight watchers at home, wait until Weight Watchers is having a joining special and join and get all the material you need and learn how to use your point system and exercise points finder (you should learn it the first night) and then quit and work on it at home. But I would highly suggest you find someone (even if online) that you need to be accountable too each week on your weight history.
Hope this helps!
Melissa