First I removed the noise and some washed-away parts of the image. I also Burned/dodged in some places to make the photo better, since some parts were to dark and some were to light.

Then I coloured the image. The colour map you see in the SBS image is made of many layers, some are set to overlay, some to colour. I coloured with various brush sizes and hardness and opacity, with mouse! This took me a lot time to do, but the hardest (and longest) part is yet to come....

Now, the image is coloured and all, but edges are still to blurred.... I tried using many filters, but the edges were still blured.... Some filters would even create some kind of glowing blur on those places....

So, I came up with an idea how to make the edges sharp. I would select a part of image a few pixels beside the edge, copy it and stretch/move it, so it gets over the blur, and still looks natural. I did this almost everywhere possible. I also took care not to over-stretch it, since it would make some body parts bigger (so the rule was right to left, bottom to top - for example my mum's arm - for the edge on left I took a piece of her arm and stretched it, but for the edge on right I took a piece of background grass and stretched it... Hope you get what I'm saying). =)

Here are some comparisons after this. Note that I added a high pass filter before the change, so some parts are even sharper. =)

Now, my technique sure made edges sharper, but faces were still blurred, so I used some parts from these source images, and edited them to match the shading and shape to enhance the faces (I also used the two girls source image for my mum friend's cheeks, but I couldn't fit them in this image).