Hi Jennifer!
Well congrats on your first Disney trip later this year! Bounds of fun and excitement await you and your family at the "Funnest Place on Earth!"
I think you do have a little time before securing a fall vacation. Historically Disney has been known to offer deals for the fall as the end of the summer approaches. I check their "Special Offers" page frequently to see if something of interest comes up throughout the year. You can access the "Special Offers" site by clicking here. Currently, they are offering free Dining Plans for 5-night stays at Moderate and Value Resorts, which now includes fall dates.
If you are a member of AAA, they are also known to offer good deals for Disney as well.
But if you don't see anything in the next month, I would go ahead and secure my vacation. If something comes through in the interim, I would contact their booking agents. There have been instances when they've honored deals well after I've secured a reservation, provided that I have the proper pin codes and such.
Good Luck! Hope you find just what you need!