A warm welcome to the world of travelling with JY. I am sorry to hear of your recent loss, but you are not alone, there are many people who have lost a loved one that travel on these tours. Also many like you take a tour in memory of that person. These tours are full of laughter but sometimes there can be tears and that's not a bad thing.
Don't worry about the age thing at 57 you will be fine, I am that age and have been travelling with JY since 2006 also the age I think in coming down a little bit now, there are many people on this community who are younger than you.
I have been lucky enough to travel on 11 tours from Austria-Kenya-USA and even as far as New Zealand and many other places as well. I have seen some great sights and met some lovely people along the way.
I have not been on the tour you have picked, but it gets great feed back so I am sure you will have a great time.
Any other questions just ask, and I am sure someone will have an answer.
Cindy