I'm not a rod builder and looked through this forum on a whim....
Eric, I'm truly sorry to read about your little guy. I hope everything is going as good as it can. It's my opinion that your son is in the best of hands there. My youngest has a birth defect and we spent a lot of time at Children's with him needing 17 surgeries over the last 21 years...a couple of which were life threatening...so I can kind of feel your pain, friend.
It was nice to see the wooden Mickey is still there
Our (or my) experience was that the days seemed to have no end during some of our stays. It was the little things that brought smiles to everyone. If or when your son is mobile, I'll encourage you to wander around and explore. Our last visit was last year and they still had some awesome fish tanks in different wings of the hospital. The play area is nice with both outdoor and indoor things to do. Wheel chair rides/races down the covered parking garage ramp were fun when mom and security weren't around And my boy liked to see how high he could get the speed control reading on one of the parking floors.
Probably one of my boys favorites was to fly paper airplanes, gliders, or those little rip cord helicopter thingamajigs in the big glassed in open area. We'd wait until later in the evening, after most people went home...launch them over the safety glass...race for the elevator...retrieve them...and do it all over again. Hopefully the increased security staff will look the other way.
For you and your wife, the reading room/library on one of the upper floors was a nice get away at times. And I don't know if it's still true or not, but there used to be individual sleeping rooms on one of the upper floors....if you gotta get some much needed sleep during the day.
Also, there are, or were, some trails to walk around some sort of a lake down the hill in the general direction of UW. I found it a nice moving meditation, if you will...it was also a place to curse or cry...whatever the need may be
You're probably all set up with lodging, but I'll throw it out there anyway. Consider the Ronald McDonald House. It's within easy walking distance. My wife and I stayed there a couple of times. The rooms were adequate, the locker room type showers were clean, it was quiet, and all we had to do was sign up for a chore or job. Prior to finding it, we had been staying at the Silver Cloud for a reduced rate....that's another thought...if you're already at Ronald McDonald...consider doing a night or so at the Cloud or a similar place....the indoor pool was a relaxer or fun activity for my other boy.
That's all I can think of at the moment....hope this helps until you and your son can get out there to enjoy the new fly rod.
All the best