Sorry to hear of the loss of your husband! I lost my dad when I was 10 so you're probably a tough cookie like my mom was. She had the flying with two kids thing down long before my dad passed... then we weren't able to travel much. Glad that you still can!
I have to say that I can kill tons of time in an airport with my similarly-aged children (now 11-15). There's always something to look at, someone's hungry or needs the restroom, etc. I wouldn't schedule a connection to avoid bored kids specifically. Once, on an amusing note, they were interviewed for a video the airport was doing (didn't make the edit but oh well!)
The other Big Criteria for me is how well serviced your connection and destination are. If you're flying SFO to LAX, well, yeah, there will be 10,000 other flights. But Hawaii out of DFW? Maybe but that would be a bummer, especially as someone mentioned, you'd probably get separated.
A shorter layover might work for the way back, if there are a lot of flights. But on the way over, you don't want to miss your Great Hawaiian Adventure!