It sounds like your injury hasn't slowed you down one bit! That's great to hear. I'll bet your kids keep you pretty active and busy. That's encouraging for me as my injury wasn't a complete tear. I wish I had an answer to your question concerning what to do about surgery, but I think (only my opinion based on what I've read here and what my surgeon told me) that it will be up to you based on how much does this injury affect your daily life, how much it affects your training and how important is the marathon.
What I'm trying to deal with now is they found a large tumor on the MRI on the same leg as the tear. (7cm x 3.4cm x 2.4cm) I'm not sure if it has anything to do with my hamstring tear but I need to deal with it anyhow.