My 7 almost 8 month old son won't hold his own bottle. is this ok?

My first child held his bottle by 6 months, he's 9 years old now. I feel like this one is taking so much longer for each milestone. He isn't crawling, he uses a pacifier (the first one didn't use one), I feel bad comparing but I can't help but worry and wonder why he seems so far behind the first one.