'Ariel Red' hair dye help

1. What is the longest lasting red dye? It's been 15 years since I explored red dyes and I don't remember what's good and what's bad.

Special effects or directs are best. For a true red, mix together an orange based one and a pink based one.

You think there's enough damage in that where the dye won't just wash out right away? Does that even matter?

Yep, that should be fine.

3. Any other useful advice about keeping the red dye put? It's still a couple weeks away, is there anything she can to do help 'prep'?

Just this thread for keeping the colour vibrant http://www.hairdyeforum.com/index.php/topic,11009.0.html

My favourite red has always been Special Effects Blood Red.

I used to use Special Effects Nuclear Red and children used to think I was Ariel all the time haha! I used to get at least 6 wks out of an application of it over a bleached base but if her hair is coloured with a permanent dye that should be enough to get it to stick.
You might want to mix Nuclear with something like Blood Red to get a true red though, Nuclear is like highlighter pen red and fades orangey.
I didn't do anything special to keep the colour vibrant, SFX reds have awesome staying power! (If she's used to permanent dyes though make sure she expects some rub off onto the collars of light coloured clothes and knows that if she gets caught in heavy rain she will be covered in dye!)