Blahages

Right now, my dad has a machine which he uses, as well as my three sisters. His user is unrestricted, however, my sisters are set as restricted accounts, and I wrote a little batch file that runs on start up, hidden, which after 30 minutes displays a warning that they have 2 minutes, and they will be forcefully logged out. After the two minutes are up, the machine logs out. They're not too technical, so none of them knows how to stop the logout. So, that's not a problem. But, After they are forcefully logged out, they can log back in, without any problem. My question is, I don't know if Windows logs this or not, but is there a way I can view the number of times specific users log into the machine each day? They're all supposed to be limited to three 30 minute sessions a day. I don't care about forcefully restricting them to the 3 times, BUT, I would like to be able to see if one has been logging in, say 5-6 times a day, when either nobody else is here, or nobody is paying attention. One of them has a long history of lying about anything and everything, and I know without a doubt that on several occasions she'll log right back in, or get on 5-6 times a day. I just want something that confirms that. I'm not looking to use any bloated third party tools, which have 500,000 "features." I just want either a way to check the number of logins manually, or something little that will tell me easily the number. Thanks