It's not uncommon for people to have dreams about their dead relatives immediately after they passed on in a manner that is comforting, and seems to be telling the person that they are in a better place, and to not worry or mourn about them.There are stories of people lucid dreaming and coming into contact with people looking for answers, and then asking if the real people will know or understand if this interaction took place, and the dream people said they would know in their own way. The dream person implied it was a subconcious process. Other between life hypnotic regressions imply that giving alive soulmates/relatives dreams is a normal skill most souls unless they are very young, naturally have.
Depending on the vividness of the dream, I would either say it was a symbolic projection of what they represented in your life or their roles or personalities relating to or depending on the central theme or symbolism of the dream, or that your dead relatives were trying to be in contact with you in a reassuring way to help or guide you.
Rambling a bit here about my own experiences..
There are soulmates I don't talk to anymore, but every so often they'll pop up in my dreams and we'll be very friendly and close again. In one instance, an ex-boyfriend asked me why I didn't show up or respond when he was in my city on business as it was implied by my conscious intention that I had wanted to get back together with him and it's hard to explain, but that was planned to take place (things happened and I didn't get the message in time). I still see him in dreams occasionally where we talk to eachother and I tell him I miss him and ask how he's doing. My soulmate dreams are more vivid, and I do feel like I am in contact with a part of them. In one instance, this with a different soulmate, I could smell him and see and feel the texture of his skin. I had a dream about him immediately after I met him and dream about him sporadically even though we never talked too much and I know his conscious self at the very least came to the conclusion that there was something different between us. How much he acknowledged it, I don't know. He was married and had a kid but I dream about him every couple weeks.. twice this last week. My understanding is I have a lot of history with him.