When it comes to gender roles and the like I really don't like the arguments put forth. A lot of it is blamed on "society" and how the media portrays how women and men should behave, at least from the feminists I've met. I've also met some feminists who, like me, saw how the argument against society was a scapegoat that frees blame from the individual. In saying that, of course there will be times in your life that you are discriminated against for your gender and the like, heck in Melbourne most of the bartender jobs advertised specifically ask for females and will throw your resume in the bin if you are male. What my overall message in regards to your mother's view about some instruments being too "girly" is, who cares what others think or how "society" wants you to behave just do what you enjoy.

Now that I got that small irrelevant rant out of the way, my advice for kids may be valueless as I'm only by relative terms a kid myself (not one you'd raise though). However I think one of the most important things for children is that parents equip them with the right tools and thought patterns that allow them for intellectual growth and development, as well as disciplining them to rely on themselves when it is the only option left. While there are some circumstances that merit 12 hour babysitters for your children, it would be even better to find babysitters like family who will challenge your children to learn and develop.

Things such as critical thinking and the notion to question everything are paramount to the growth of children. I also think it's important to treat children like equals, not sparing any details unless it would be harmful to their fragile minds. Small things like responding to questions that would require complex answers (in a way that a child can barely grasp if too complex) and valuing their ideas just as much as you'd value an adults idea (for things like parties) but incorporating them in ways that will satisfy the children and also leave room for the more beneficial ideas if the child's is too ridiculous.

I'd agree that nurturing your children is very important as I'd imagine most people would on this website, but I think some time should be allocated to teaching your children the principles that will help morph them into civilized people with strong intelligence. Children need to be loved to avoid being callous shells, but also need to be disciplined and equipped with the knowledge and thinking patterns of critical thinkers so that they can independently evolve themselves at an early age.

Again I will reiterate in saying that my advice may be terrible since I am no where near having a child of my own.