I could not find the chords on any sites, so I watched a few videos of her playing this and this is what I 
got. First time sharing chords, but I think this is correct and I will tell you some of the tricks she does.
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It's Gonna Rain
Amy Cook
Featuring Robert Plant
Capo 2nd fret (Chords played as if 2nd fret is open)
(Chords shown at the bottom)

            G
It's Gonna Rain
                Em
Oh, it's gonna come down hard
                          C                     D
There will be flashes of light coming from the sky
                G
Shining in the dark
                G                    Em
Oh, It's gonna poor and fill up your cup
                         C                  G* 
And when it gets to the top it's not gonna stop
                    G
It will flow you a river

                 C               G
Oh, it's gonna bring fields of roses
                     Em                       C
You won't go until you've had more then your fill
                 G*
More wins then losses

            G
It's gonna rain
                 Em
It's gonna get colder
                C                       D                   G
It used to be said," It's not quite as bad now that we're older"

                    C               G
Oh, it just might bring fields of roses
                     Em                       C
You won't go until you've had more then your fill
                 G*
More wins then losses

             G
It's gonna start
                          Em
Yeah it's gonna get real quiet
                    C                    D
And A bird on it's way to some far off place
                         G
It's gonna sing you to sleep tight

                    C               G
Oh, it just might bring fields of roses
                     Em                       C
You won't go until you've had more then your fill
                 G*
More wins then losses

                    C               G
Oh, it just might bring fields of roses
                     Em                       C
You won't go until you've had more then your fill
                 G*
More wins then losses





G= E|––3–––|
   B|––3–––|
   G|––0–––|
   D|––0–––|
   A|––2–––|
   E|––3–––|

G*= E|––––––|
    B|––3–––|
    G|––4–––|
    D|––5–––|
    A|––––––|
    E|––––––|

Em= E|––0–––|
    B|––0–––|
    G|––0–––|
    D|––2–––|
    A|––2–––|
    E|––0–––|

C= E|––0–––|
   B|––1–––|
   G|––0–––|   She plays around with hammering on a pulling off on the d string
   D|––2–––|
   A|––3–––|
   E|––0–––|

D= E|––2–––|
   B|––3–––|
   G|––2–––|
   D|––0–––|
   A|––0–––|
   E|––0–––|

She also does a little riff when going from G to Em
E|––3––3––3––0––|
B|––0––0––0––0––|
G|––0––0––0––0––|
D|––0––0––0––2––|
A|––2––0––0––2––|
E|––3––3––2––0––|


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Hope this was somewhat helpful.