My daughter was the same at 9 months: nursing every 1.5-2 hours during the day, and frequently (6-8 times) at night. It's totally normal. Is the night-nursing getting to you, or are you okay with it? If you're okay with it, there's no reason to fight it. Your child will eventually give it up on her own- but there's no telling when that will happen.
Regarding the constipation, breastmilk is the best thing you can give your baby, since my understanding is that it's a natural laxative. (I'm not pulling this out of my rear- this is what my pediatrician told me.) So long as you are nursing on demand, your baby is getting enough milk. At 9 months, you probably want to offer the breast before the solids, to encourage your baby to fill up on the more nourishing, more poop-encouraging breastmilk instead of the less nutritious, constipating solids.
What solids are you giving? If constipation is a problem, you should probably avoid bananas, apples (the skins contain pectin, which is the stuff you use to make jams and jellies firm), white bread, white rice, cheese, and cow's milk dairy products. Fruits and vegetables are great at fighting constipation- prunes especially- and if you want to give dairy, yogurt is probably the thing that is least likely to cause pooping problems.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"