No, that is not correct. Remember that we are looking for whether they have the disorder or not.
Whenever you see cousins marrying, you usually are thinking “recessive”.
Remember that each child is independent. The children born before have no bearing on the future. It’s like rolling dice. Irrespective of whether your first two rolls are 6 and 6, or 1 and 2, the probability of your third dice roll being a 6 is still 1 in 6.
This might be time to start using Punnett squares… this one would look like this.