What happens to our loved ones when they pass away

Ever since my cousin passed away in the UK 2 years ago, my aunt, her mother, has been worried, preoccupied, concerned, with her daughter soul’s resting place.
The reason of her concern is because my cousin was not a believer.
As a believer myself this things do not worry me, as I know it is not up to me, to us, to decide if we go to heaven or hell.
I believe that by the blood of Jesus Christ, his sacrifice, and his resurrection we have nothing to worry about, death has been conquered, and he paid the ultimate price for our sins, even for those who were not conceived at the time, as we were already in God’s plan.
Catholics believe in purgatory, and I find this to be troubling, because, based in what they believe nothing can stop us from going there. This is where my disagreement lies, because of the crucifixion, and Christ’s taking on his shoulders the sin of the world, he has lifted that burden from us.
Another cause of disagreement is that good work may influence in God’s decision. As I said earlier, it is not up to us to pay our way into Heaven, this is through God’s mercy, and through the suffering of his son Jesus that we can rest assured that we have a place there, at the right hand of God the father.
A good friend of mine says that the moment when we die it is over, that we do not go to heaven, that we remain in God’s memory until the time of the second coming of Jesus, and the resurrection of our bodies. I cannot agree or disagree with that opinion. I respect it because it comes from somebody who has lived longer than me, and who has more knowledge than me.
It is just a bit unsettling for some people to accept that because when Jesus is on the cross and he turns to the thief and says: “Truly I say to you, Today you will be with me in Paradise”, that statement seems to say that the moment that that thief passed away he would be with Jesus in Heaven.
As far as my cousin is concerned, which was the beginning and the relevant part to this blog, I do believe that she is in heaven, because, as I said earlier and will repeat, not because of who she was and/or did but because of God’s mercy, and the sacrifice of Jesus Christ, our savior, to whom be the Glory.