While you don’t need to use a LL in the morning, do book one and modify it later in the day. Always book immediately upon entering as it sets the clock for when you can book your next one (2 hrs from the last booking or when you tap in to a ride, whichever is earlier.) so if you wait until 11 you will have missed out on 2 rides you could have saved for the busy time of day.
Speaking of busy time of day - take a break mid day. Let the kids chill out, take a nap/shower/whatever and head back once the mid day crush is over. Catch the second parade as it’s better at dusk/dark.
My suggestion for DL is to book Indy and then carry on with your morning. Indy goes down often so if it does that will convert to a multiple use pass that then expedites any other LL you get. During busy times this can be a game changer. Your 6 year old might not be tall enough for Indy but you can utilize rider swap and your 9 year old gets to ride twice - bonus!