I would definitely give them each their own mIRC folder; completely independant mIRC installations.
This allows each of them to customize all they want with sounds and scripts and logs and downloads, without the other one complaining about changing stuff or deleting stuff. mIRC is such a tiny install anyway, so if one screws up Big Time where mIRC needs to be re-installed, the other one doesn't have a nervous breakdown.
Also, mIRC can be easily duplicated with multiple locations on your system. There's no need to use the installer each time... just copy/paste.
- Raccoon
PS. You're knowingly encouraging someone's daughters to IRC? With the rest of us filthy scum??
