If you are worried that she's going to find you needy... tell her plainly something like "I'd like to have more frequent sessions for you for at least the short term; I'd like to work on X and I think that seeing you more frequently would help my progress for a while. I'm hoping it'll only take Z long to start with progress, but we could talk about it at say, maybe Y-date?"

Then you're explaining WHY you would like more sessions, with a clear goal in mind.. and providing a date to re-evaluate the necessity of the more frequent session. That's proactive, not needy