How much cash for incidentals?

<p>Our D ‘junior’ at HS is also on AT&T family plan with us and Inter Cell Phone calls (with in the plan) are free coast to coast. We keep in touch thru cell phones only when outside. The calls to 50 states are included in the plan minutes. The plan include the unlimited data plan so she can email from the iphone too. We are planning to keep her on the plan when she goes to college next year.</p>