In your original post you said:

When the triplets were born I got a message that Four is enough. It didn't count the adopted girl. It's like she doesn't exist.

As has been explained, because you went past 4 with triplets, and there is no message for 5 kids, you received it after the triplets were born.

There are only 2 messages - 4 is enough, and No Vacancy after 6 kids.