C.V.
Talk to her, but remember:
Equal treatment of children is a wish, and an unrealistic one at that. It simply doesn't happen, even with the most well-meaning parents, because every child is different, with different needs and personalities.
It's not uncommon for grandparents to latch onto the older child. They came first. But when it's becoming obvious, you should talk to grandma about it. Perhaps she just needs some more time one on one with Victor, so they can get to know one another. After all, she had 3 years alone with Joe before Victor arrived.