Can I claim my mom for previous income tax - 2005-2006-2007, and now 2011

An amendment for the returns PRIOR to 2007 is a waste of time, because the three-year statute of limitation to claim refunds has passed.

If your mother has met the Substantial Presence Test, AND you provided more than half of her total support, then, yes, you CAN claim her on 2007, 2008 and 2009 by amending those returns.