Firstly, I don't see balance as at all the same thing as "having it all." Living with balance for some people - including myself - often means simplifying - having less, not more. The more you accumulate and add to your life, the harder it is to maintain balance - at least in my view.
Secondly, I admit that I don't have children (yet), and from what I've heard, life becomes infinitely more chaotic once that happens. However, I do have a busy full-time job, two online businesses (including 5 blogs), a new husband, and am in the process of buying a home, as well as fixing up my husband's home to sell. Life is a complete whirlwind!
I also freely admit that despite my best efforts, I don't always live a balanced life! However, seeking that is a value that guides me, and I am able to achieve it to some degree more often than not. So before you give up on balance altogether, consider these 3 points: