Oh Aggi, I am so very sorry for your loss. There are lots of us here on the board who can sympathize. What a wonderful mommy you are to see that she is no longer in pain, as difficult a decision as it was.
When I lost one of my babies years ago, I found a passage from the writings of my religion that referred to "the souls of the lesser creatures". And that really helped, because I had incontrovertible proof that our pets do indeed have souls, which means that we will see them again someday.
Hugs and ore hugs to you.