Her class was similar to mine. Now that I think about it, she probably struggled more with transitioning up in class.
Therein lies the rub Cynique, for you see that it is actually harder for someone trying to be middle class than for someone was was born into it over a period of generations.
For example of grew up with the "get over" mentality. It was not a mentality that my mom instilled in me, it was one I learned in the street. It encompasses everything from cheating on tests, beating fares, shoplifting, selling drugs, not paying of lying on taxes, etc, etc. This mentality sees nothing wrong with any of these activities -- in fact you are a sucker if you don't do these things.
So while middle class values are indeed available to anyone, the lower you are on the social-economic ladder, the more difficult it might be to achieve. Of course the transition is easier for some than others. Staying in the middle class, is particularly for Black people -- there are quite a few new books written on this subject from different angles.