Shawna-- I haven't posted much but had to respond here. My kids are the same age as yours (no, that has nothing to with anything...). Last year was my first half -ok, second RACE ever- and I went into it just like you, hoping to finish under 3 hours. I could have pushed harder and taken a few less pictures but finished at 2:50 and felt great the next two days in the parks! This is so key. I went down with 3 girlfriends who are more athletic than me and they finished between 2 hours even and 2:30 and 2 of them were really hurting, had no character/castle pictures and couldn't thoroughly enjoy the two days we had. So, stick to your plan and enjoy. This year I was planning to go more for time but in the last couple weeks I've reminded myself of how much fun I had and am hoping to just shave 5-7 minutes off last year and still thoroughly enjoy every minute.
Side note---perhaps this is like labor, awful as you're in the middle but then you forget about the pain and do it all over---it wasn't easy last year, I didn't follow my 4:1 plan (too excited, I guess---just running blissfully toward the castle) and had to walk miles 8 & 9 because my back was sore. BUT, knowing to give my body a break and not push at that point, I believe, is what saved me later.
I guess I'm just reminding people to listen to your body AND remember this is Disney

so enjoy and take in every moment.
17 days.... good luck with training
~Jennifer