Cortenemas

You shake them, take the top off, add some extra lubricant to the tip, carefully squeeze excess air out, and ... find the exact place to insert, at an angle (some of remember the instructions for a tampon, "at an angle...")and at first slowly squeeze in the contents. The tip should go in pretty much as far as you can get it in - if you don't get it in far enough it won't get into the colon. Fold over the top to be able to get more out of the bottle.
It helps to warm the bottle under warm water or under your arm in cold weather.

The concept is that the liquid is released in past the sphincter, so it shouldn't come back out.
Your daughter might feel a bathroom urge for the first minute or so - she should breathe slowly and the feeling ought to pass.
Watching my colonoscopies, I was fascinated with how much my colon moved when I talked! - so I don't talk for the first 10 minutes after doing it.

I do them when I get into bed at night, but I have done them in the morning - and have stayed on my left side for 30 minutes. They need to be done after the morning cluster of bathroom runs.

Keep us posted. I didn't do them with my son, (his doctor didn't suggest it, and I was so stunned that he was going through this, I wasn't very assertive) and I've wondered how it would be with a kid....

If you're using the generic Teva, don't be surprised if you can't get any air out of the bottle first.  I've never been able to, the liquid comes out instead.  

I've also used them in the morning and when I was having a lot of symptoms and travelling, used it both in the morning and evening.  I tried to avoid using them twice a day for more than a week though.