The problem is not with logkeys, but with sudo. Look at the error messages:
invalid option -- '-'
usage: sudo [-D level] -h | -K | -k | -V
maybe it is due to a malformed command line.
An aside note: sorry for this, but you should definitively talk to your wife instead of spying her. Here the problem is that - given your purpose - your question is fairly on the edge of the hacking/cracking rule and your thread should be removed. Is there any reason for preventing me from doing that?