Do they have a seniors price? And can you go in just to watch the grandchild?

I believe Matt is correct. My 11 yo went on part of the course by himself. We were on the platform watching.

Don't think so on the senior price, but you can watch for free, provided the kid is old/big enough and doesn't need an escort.

The senior price is $42.99. Anyone is welcome to come and watch for free : )