Stay Married

Triathlons are best for singles with lots of time, or triathletes married to each other

If you have a family, train with your spouse and/or your children as much as possible

Other tips to minimize your time away from family: run and bike from the home; run or commute to work on your bike, run or bike during your lunch hour, limit time spent training with groups (group activities inevitably add a great deal of time for traveling and socializing), compete in short triathlons requiring less training, and maintain your bike yourself

Follow a flexible training schedule that can be easily adjusted to family priorities (and demand of work)

Put family needs first when working out a balance between training and family

Treat the trip to triathlons as a mini-vacation for the family and take the opportunity to sight see and enjoy the travel.  My wife was happiest if we stayed in a good hotel.

Maintain a long term perspective. If it is not practical to prepare for a full length Ironman now, you should be able to fit it in after the kids are grown, or you retire, or have a less demanding job