Slipping=foot/pressure on the clutch pedal. You slip the clutch to get moving from a stop (partial clutch engagement). The clutch is fully engaged (not slipping) when your foot is on the carpet, or fully disengaged (not slipping) when your foot is on the clutch pedal and the pedal is pressed to the floor).
With a daughter I'm sure you already know this but BE PATIENT! Do not scold, give pointers.
Beginner course: Start with throttle/clutch control. You can shift from the passenger seat while the student concentrates on the wheel and pedals. Left feet are only for clutches and foot-rests! If she gets the car moving but buckin' like a bull calmly tell her to take both feet off the pedals. Have her imagine the pedals are linked by a rope and pulley where only one pedal can be down at a time. Half throttle=half clutch (a little abusive to the clutch but it's a metaphor/starting point..) No throttle=press the clutch (for stopping or shifting), no clutch=press the throttle (for accelerating/driving). Again, be calm. If she stalls the engine give slow deliberate instruction: "Push in the clutch, take your foot off the throttle, turn the key..."
Intermediate course: Draw out a picture of the shifter pattern. With the engine off call out random gears and have your daughter move the shifter into that gear until it doesn't take any thought. It's not hard if you know 1-2 equals towards you plus up or down, 3-4 equals hands-off neutral position plus up or down, and 5-R equals away from you plus up or down. Beginner tip: each gear is roughly good for 10 MPH in normal city driving. 0-10 1st gear, 11-20 2nd gear, 21-30 3rd gear, 31-45 4th gear, 46+ 5th gear. Revert to beginner course (you shift from passenger seat) if she gets flustered.
Check-ride: Student is in full control. Only intervene with suggestions, and only after you count to 10 Mississippi. For example, student is cruising 60 MPH in 3rd gear... (Count silently in your head: 1 Mississippi, 2 Mississippi, 3 Mississippi...10 Mississippi) "Maybe you should shift into a higher gear."