Okay, I am going to add my own two scents to the discussion, Sally

I have been in your situation, where I questioned my first novel and if it would be long enough. That was me at the age of fifteen, and I didn't complete my first "novel" in terms of words until I was sixteen.

As far as your outline goes, I think it looks great as far as length.

But the most crucial key for me in terms of reaching novel length was reading other novels while I am writing my novel. I guess it's because then those styles soaked into my own style and therefore helped me finish my first novel.

I hope this helped.