I think it is normal to feel both happy and sad at the same time. I'm looking forward to having time and money to finally focus on my wants, but I know I'm going to really miss having my children here with me all the time. My oldest heads to college in the fall. She's only going 90 minutes away, even though she wanted to go across the country (too expensive). The youngest, who is 15, says she wants to go to a school in Florida, which is a long way away. I think that will be hard, if it happens.
I also think some women have a hard time figuring out what the next stage is. I have struggled with that a tiny bit myself as far as if I want to continue with writing full-time and maybe go back to school and do something else part-time. I haven't decided just yet.