Re: Supply decrease or self weaning?
I personally know 3 babies who self-weaned at 9-10 months. It's a super-distractible, super-headstrong phase, and some babies just decide that they're done.
That being said, it doesn't sound like your LO is self-weaning. First, while your pump output has dropped, it hasn't dropped that much. A lot of moms experience a "pump slump" in the 8-10 month timespan, as the baby transitions to eating more solids and the pump starts to wear down. Second, your baby is still nursing. Maybe not a lot, but if you're with her she does nurse even during the day, when many busy babies refuse.
I think the way you deal with this is with patience, persistence, and repeat offers. If you're home, you offer to nurse when a couple of hours have gone by. Make it playful and low-key. If the baby latches on for even just a second and then toddles away, you still reminded her that nursing is there for her. At work, just keep doing what you're doing and think about rehabbing your pump (maybe the embraces need to be changed, maybe you need new flanges).
I think you'll make it to a year with no problem.
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!"