Converting Sibelius MIDI export into a Piano track

I was called out to go record a piano session by an elderly lady who I have worked with in the past. She likes to compose music for Puppet Shows and small Musical. She does a pretty good job despite the fact she has no musical training and cannot even play the piano. She uses Sibelius notation software.
So She had a pianist come over and using a Costco Yamaha Digital Piano had her play the sheet music. Because the Yamaha sounded so bad I just recorded MIDI. There where a few issues with the notation the pianist pointed out so she opened her Software to make corrections. So I had a chance to mess with it while they where fixing things and find a MIDI export function?? SO I grabbed my USB stick and exported the 8 songs we were recording.
So now I have two MIDI versions of each song and each has issues.
1. The ones played by the pianist have dozens of miss played notes I will need to fix, Also a lot of small timing issues. This will take about 3 hours I guess and the timing will probably still be off. ( No metronome used because she couldn't cope)
2. The Exported MIDI files are perfect,, too perfect, They lack any dynamics or human qualities and there is no sustain pedal.

So I ask anyone here, and thank you for you taking the time to read this... Which way would you go? Edit the live version or add human touch to the notation generated tracks. And how is that possible?
The old girl just wants it to sound like what was in her head, The resulting tracks will be used as a performance backing track. She is not rich either.

Excellent! I'll give it a go. I was thinking of hooking up my sustain pedal and adding that, trouble is I'm not a piano player and would only be guessing at it's placement.
Just downloaded the trail version of Real Pianos and a few other freebies from KVR. See if that helps. TTS-1 has sad sounding piano patches

Thanks for you help Chappel. I just tried your first idea and it sort of works, I guess you have to play with the settings to see what happens, So I opened the event list to look my damage  and was surprised that the lyrics are inserted as events!
On an after thought I hit undo ( the Velocity randomize) and looking at the original file was a mix of velocities from 70 - 101? Wonder how they were generated? I was expecting all one value. Maybe Sibelius has a auto randomization feature she was using. 
But a big improvement was made by using RealPianos! It seemed to take the mechanical edge off. I'm going to buy it when demo runs down.  Getting sleepy so tomorrow will try the sustain pedal. Do piano players step on them as they push the keys down then release when they lift their hand up?
I have done tones of event editing and yes, it's a time suck. That's what I'm trying to avoid. 8 songs would take to long to do a lot of editing too. I think she'll be pleased with the Sibelius MIDI export version if I can get them a little more natural sounding.
The version played by the pianist sounds even worse when I play it now, It lurches along pausing and you can tell it's sight read.

Sorry That should be Truepianos. Thanks, That's important info if I try to insert the cc manually. I'm going to try the pedal and record in a new track, It should effect all notes in channel 1 ??? I hope. Anyway, still half a cup of coffee to make it through first. Sun just came up.