Im sorry to hear the unfortunate news about your wifes situation, and that is very strong of her to want to have you go and enjoy the trip, kudos to her.
Ive taken many solo trips to DLR, many while I worked there, haha. I love it, it gives you great time to just roam and explore the parks in the perspective that you want to. What days are you going? Maybe I could pop down to the parks for the day or something and hang out with you and give you some company if your interested? I could give you my CM discount on merchandise if that makes the offer sound any better?
But alone or with someone, you will no doubt enjoy the trip.