Having obtained my PhD-degree only recently, I can tell you that you should persue it only if you really like doing research and specializing on one (tiny) subject matter.
What you certainly should NOT do, is persue it because other alternatives (e.g. working in a company; teaching; or something else) are less attractive or difficult to manage due to your family commitments.
So basically, going for a PhD should be your first primary choice, and not a choice because other options are less desirable.