Portrait for christmas gift

Last August, my father was diagnosed with Leukaemia and was in full remission and back to work by Christmas.
On his birthday in May this year, I took this shot of my parents (not a posed shot as such - no flash, etc). Whilst the shot itself may not be the best, I liked the context of it.
Now, I want to print this off on A3 size, frame it and give it to my parents for Christmas this year.
I have played around with it in PS, creating layers, desaturating the background layer and reducing the opacity of the top colour layer, playing with curves to slightly increase contrast, etc.
Now, can I borrow from the deep, deep pool of talent and experience to get your opinion on how I can make the photo really worthy of a largish print? I have posted the original, unprocessed version below.
I accept the photo is a little soft.
Even if you think that it isn't worth printing large (apart from my own sentimental reasons for doing so), feel free to let me know.
(For whatever reason, I don't generally feel comfortable posting images of family members anywhere on the net, but really want to tap into this the Dslrusers resources for this one).
Many thanks.

On his birthday in May this year, I took this shot of my parents (not a posed shot as such - no flash, etc). Whilst the shot itself may not be the best, I liked the context of it.
Now, I want to print this off on A3 size, frame it and give it to my parents for Christmas this year.
I have played around with it in PS, creating layers, desaturating the background layer and reducing the opacity of the top colour layer, playing with curves to slightly increase contrast, etc.
Now, can I borrow from the deep, deep pool of talent and experience to get your opinion on how I can make the photo really worthy of a largish print? I have posted the original, unprocessed version below.
I accept the photo is a little soft.
Even if you think that it isn't worth printing large (apart from my own sentimental reasons for doing so), feel free to let me know.
(For whatever reason, I don't generally feel comfortable posting images of family members anywhere on the net, but really want to tap into this the Dslrusers resources for this one).
Many thanks.

