i think you are being a little harsh on your daughter. grounded for being two minuts late? c'mon! and increasing the punishment every time? seriously?
rules are there to discourage bad behavior, not stop it altogether. you will never stop your daughter from doing things she wants to do, you can only prevent her from taking it too far. you will be fighting a never-ending battle if you continue to ground your daughter in this manner.
why do you think she drank your alcohol? because she's a "bad girl"? no. it's because she's a bored girl. because she is stuck inside all day long with nothing better to do than be sedentary and rummage through the cabinets and closets looking for something to do once she's sick of TV, music, and the computer.
you must understand, this is a very common yet tragic mistake that parents make. you cannot take away activities and ground kids if you want them to behave in a healthy manner; they will only find ways around your rules and look for new ways to have fun - which are often unhealthy.
instead of being restrictive, which indirectly encourages her to rebel and do things you wont like, you should be supportive. not supportive of whatever she wants to do e.g stay out all night (thats crazy), but supportive towards her leading a healthier lifestyle. instead of punishing her negatively, punish her positively - by making her do something good that she might not necessarily like.
for example:
tell her you will un-ground her if she does one of the following:
gets above a certain G.P.A
joins a certain after-school activity you'd like her to participate in
joins a sports team
pledges to exercise a certain amount of hours a day
goes to church
volunteer
the opportunities are endless.
I would advise you to keep this in mind:
first, this cannot be an instantaneous lifting of the grounding, nor can the grounding come back under the slightest infraction. slowly give her more and more freedom (and more leeway if she slips up) as she continues to consistently do what she pledged to do. if she wants to have lots of fun, she needs to balance it with lots of work.
also, i beg you, please dont freak out as she grows up and makes mistakes. it's very likely that she WILL smoke pot one day. she WILL throw a party at your house one day. she WILL get drunk. she WILL have sex. If you punish her by grounding her every time she does something like that, you are only instigating a war between you two. you have to accept that these things are inevitable and you have to allow certain things to slide. KIDS WILL BE KIDS. theres nothing you can do about it. It's your job to prevent your daughter from taking things too far, not punish her when she slips up. let her make her own mistakes. when she smokes pot, make her do 50 math problems - you cant do math if your stoned. when she throws a party, make her deep-clean every nook and cranny of the house. when she gets drunk, make sure she gets so drunk she'll never want to drink again. if she smokes cigarettes, make her smoke a pack in under two hours. It's like supervised mistake-making. like: "OK, so you want to do these stupid things? well, heres the dark side of these things, heres the extra baggage that comes with making mistakes, do what you want but at your own risk". it's all about teaching responsibility, not punishing for irresponsibility.
heres how this attitude plays out in the long term:
if you continue to just punish her, one of two things will happen:
1. she will rebel so furiously that you will be hard pressed to send her away.
or
2. when she goes to college, or leaves the 'nest', she will realize that the god deity [you] who would punish her whenever she does something wrong doesn't have any sway over her, and she can do whatever she wants. now, she is doing this and that risky behavior without knowing the real dangers, without any awareness, without a sense of balance in everyday life, and without supervision.
wouldnt you rather she make supervised mistakes, rather than unsupervised? if you let her make these mistakes while she lives with you, when she leaves she will have a sense of responsibility and will not go crazy partying all day and all night in college.
i see this at college campuses all the time - there is a clear-cut division between students who's parents have different parenting styles. the ones who have supportive parents who let them party a little in high school develop a distaste for the party life early in college and end up being responsible adults - particularly the ones whose parents would actually drink with them (european style - glass of wine or beer at dinner once or twice a week, a little bit more at special events like weddings), that way the kids learned responsible vs. irresponsible drinking early on. the kids who's parents were abstinence only sticklers and banned any drinking would go and buy a case of beer every few days and get drunk at any opportunity.