J.A.
I was in the same boat. My fraternal twins are now 4 1/2. My son needed much more attention as an infant and my daughter was quite content sitting in the swing or bouncy chair. She was usually always happy and he was not. I always felt so guilty about spending more time with my son than my daugher. But as you know with twins, you have to do whatever keeps you sane. At about 16 months the tides turned and my daughter became more of a handful and needed me and my son mellowed. I have noticed this over the past 4 years. They tend to trade off who needs me more and I figure in the end it will all even out.
I think you give each of your kids what they need when they need it. There will be times that your daughter will need more attention than your son, and you will give it to her, just as you are giving your son now.
So hang in there....the first year is tough with twins no matter what. When my kids were younger I often felt guilty because they didn't get much one on one attention. But now at 4 1/2, they play together so well and always have a playmate. Their relationship is so special. Honestly, they don't know what it is like to be the only child. When I had another child when they were almost 3, it was no big deal to them. They had never known what it was like to have mom or dad to themselves.
So, enjoy every moment, because it does go fast!!! And know that each year gets a bit easier!!
J.