Empty password, Sudo wont let me set a new one.

So I've decided to give Ubuntu a spin after leaving it when Unity was introduced, and I have to say that I'm fairly pleased. I was playing with system settings and looking at options when my fiancee wants to play with it, so she sets up her accounts with a empty password and plays around, and she likes it. So, since this is our main machine, I want to put a password on her account, (she can change it later, its just a security thing since shes listed as an admin).

So, I go to the System settings and try to change it... but it wont let me put "current password" blank, I tried to unlock it, but gsudo won't accept a blank password. My first instinct is the command line, but sudo won't accept it blank there. I'm about to try and force root by rebooting into run level 1, but I doubt that will work since its a major hole that should be fixed on any modern distro.

Any options?

EDIT: Forcing run level one worked..... and now her keyring isn't being unlocked (she must have set a password, then erased it) ... Really? Over a year and nothing has changed. Ubuntu still hasn't fixed simply issues like this? .... *sigh*, sorry for the rant. Heres my solution:

At the grub menu, press "e" on the while highlighting your chosen boot entry, add a "1" after the "ro" on the line that starts with "linux" ... press f10 and say hello to runlevel one

do passwd username , then telinit 5.

Mission Completed, RTB.