Mother got a 10yr multiple entry visitor Visa in 2008 and made a couple of 6 month trips before her current trip between 01/23/11–07/23/11(expected). Sister applied for an extension before in 2010 during her second US trip but that was denied as they weren't satisified with the reason that she wanted to see more places and also since no proof was given that she will leave and no proof was sent that her extended stay will be financed. Now I want to apply an extension for my mother for 4 months. Is this the best time to apply for an extension and also what strong reason can I give them now? What documents should I enclose to support the extension filing? I make $120K per yr and have a valid H1 Visa until Dec 11. Will it cause any problem to her multiple entry Visa if she gets a denial again.