What a great mystery lies beyond death.
My mother, in latter years was suffering with the most terrible dementia. She did not remember things, she did not remember the name of her husband (my father) She did not know even that she had been married.
Then, about 2 weeks before she died, she suddenly said "Joe (my dad) has been to see me. He sat on my bed and said 'why don't you come with me?' I told him I would soon....but not just yet."
It makes you wonder....
Sometimes, in times of hardship and stress... we reflect upon the memory of those who have been nearest and dearest to us. And, those memories can migrate into our subconscious dream state. So, it's possible that your mom mentioning your dad made an impression on you to where the thought(s) of your father became dream(s) of your father. On a spiritual or metaphysical level, it is believed that the dead never really die... at least, in our hearts and minds, they don't. And that, maybe, your mother and yourself are sensing your father's spiritual presence and reassurance during this difficult time.
In either case, your dream(s) seems to reflect solace. And, we should all be so fortunate as to have such comforting dreams.