Well, there are things you can avoid to become this way but there are other things you can't avoid.
First, the fashion critique - your body will change and the fashion world will leave you behind. There is no getting around it, sadly. Your only fashion choices will be cheap muumuus and leggings in terrible loud acrylics and polyesters or you can wear men's clothing which is understated, more comfortable and longer lasting. But nice fashion and fine fabrics will be too expensive and not really fit for the middle aged body - even if you stay in shape. You won't want to put up with the pinching darts and crotch grabbing gussets and tight mid-rifts of your youth. It looks pathetic anyway on an older women.
My choice is to never wear clothing with so much as a logo anymore, no puppies or toucans or bright oversized flowers, either. Plain cotton clothing and plain make up work the best at this point of middle age.
As for the rest, you can choose to not have children. Sadly, having kids is the one factor that will drain most women of their brains and individuality. I've seen it happen over and over again. It doesn't happen in other countries, where day care is considered a goddamn right from birth and women generally want to get back to work or at least back into the adult world rather than fulfill their childrens' every Disney desire for 18 years. In the USA, women shame each other into giving up their lives for their kids, to make themselves stupid to fit in with other moms in the kid world. Guess what happens as a result? Women end up old and stupid, complaining and lying on Facebook.
These women have been left behind in the experience of living, so they latch onto Oprah and her idiotic guests as some savior from this hell they create for themselves. YES they are miserable with their Chronic Fatigue, Fibromyalgia, Morgellons Disease, Gluten Allergies, and what not. No, they don't trust doctors since MDs are largely ignoring them (rightly and wrongly.) So they turn to reiki, Qigong, Feng Shui, Yoga, mystic healers of all sorts, for some connection to the world which they rejected in favor of babies (and granite counter tops and stainless steal appliances and the Lexus) a long time ago.
So, what you have to do is never EVER lose your interests, your spark, for the lives of your husband or your children. Want to learn a language? Start NOW and always stay interested in it. Never give it up because little Johnny needs a whole new dinner cooked cuz he hates flounder (make the little fucker eat what you cooked or go hungry. It ain't gonna kill him.) Never sacrifice the time you spend on your language, or your art (but screw that scrapbooking shit), or the class you are taking on politics or history or economics. Don't have a life in the fucking car driving your children all over hell and back to some damn class or lesson. Remind yourself all the time that you are an adult, the kids live by your rules, that you are a person and your world shouldn't be infantile.
It takes enormous discipline in this screwed up USA society. You will have to fight to stay an adult. Read great literature, plant a garden, attend concerts, volunteer at a theater, read about evolution and science, pick up something like this book -
http://www.amazon.com/One-Two-Three-Infinity-Speculations/dp/0486256642
It's pretty simple but a great way to engage with scientific and mathematical understanding so you aren't totally lost in those PBS shows.
In other words, constantly challenge yourself. It will do wonders for your whole life, and eventually the lives of your husband and children who will greatly appreciate the fact that you DON'T become their family servant who dissolves into absurdity when they aren't around.