A tip for weaning off formula is to slowly dilute the formula with milk. This is how we got Jaden off, finally, at 14 months. We'd start with say, 6oz formula and 2oz milk, and then within a week, 4oz formula and 4oz milk, until we finally got to no formula and only milk. Also, if she is having trouble with cow's milk you might try goat's milk. It is the closest to human milk and it has less lactose than cow's milk. :-)