I am a married phd student in my third and hopefully final year of my studies. My wife is also doing her phd and we have a 5 year old son. I am 31, was former postgraduate students association executive, and love to sleep.
To answer the op question, it really depends on you and the context you are in. My colleagues who are married tend to struggle in balancing the demands of their studies, spouse, kids, and personal space. However it is that extra pressure that drives them forward.
On the other hand, those who are still single can afford to devote more time for their studies. It is not all rosy though because there is something about being married which makes you more focus in your work.
Having said that, i think it is a bad idea to get married and leave your spouse behind. Two of my friends are doing that, and i do not envy them a bit.
All the best for your phd, it is going to be ....an interesting experience.
Did you took Masters before PhD? Do you straight continue PhD after masters or you work 1st?