4 means you'd better have a bag you can grab so you can jog to the bus. 6 means you have to be very serious about getting to the door. 8 means you can proceed in an un-distracted, orderly fashion, out the door.
If you go by the schedule instead, you can gauge how little time you have before you must leave by using a Clock. That is, if the bus is schedules at Terwilliger at time t, t-2 would be Primrose time, then t-2-6 = t-8 for out the Time Haven door time.
XX Toilet, shower, wandering around in a daze [20?] XX Making Coffee & Carbo [10?] XX Dressing [10?] XX Eating (Optional if overslept) [10?] XX Tooth Brushing and Optional Shaving  XX Bag Stuffing (May vary from day-to-day)  XX Pocket stuffing and jacketing, grabbing lunch bucket  __ ?? Total 
I suggest putting your own numbers on these to see where they go. Subtract that from the time you need to leave for the bus, and then you'll have your latest get-up time. My minimum for all the above is 58 minutes. I know can get up late, shower and bolt in about 20 minutes, but I don't like taking my razor to work with me.
One thing you might do if you are late is to blow off breakfast in order to catch the bus. Get off #39 and go to Starbucks in Hillsdale. At least you are 200 yards from class at that point. Obviously, blowing off breakfast is not sustainable, or affordable. Your mother shouldn't necessarily be in charge of your breakfast every day.
Ideally, you would get up early enough to do everything at a leisurely pace.
Staying on time means not stopping for 5 or 10 minute conversations. If you want to have a conversation, add that to the above list. Conversations are distracting and can cause you to miss taking something, or catching the bus sometimes.
Homework is best completed the night before. If you think you can spend 30 minutes in the morning on something, you are putting yourself at risk of both not completing it, and missing the bus. This is a vicious cycle. Complete all homework, and put it in your bag the night before.
I would be interested in any feedback you may have on this. It's not found in any book, and yet it is one of the most basic things millions of people do everyday in order to leave their home. People who drive cars have less pressure because the car doesn't leave without them. However, they will be late for work if they don't leave on time.
We can talk about how this sucks, but it is kind of universal. If you have a job or a business, you can't be late for your work, your boss, your client, your co-workers, or opening the store. The Internet is changing a lot of this... but many people still have to show up at work and school (college) in the morning.
Stop ID at Wilson is 929 for the return trip.