Gabriella
It means don't panic and do something like break up with Henry or go away. Keeping your wits means to keep a level head and remember who you are. You're with Henry. Here. Happy. She will adjust to this new place, but you must give her time and you must be patient. Otherwise, you'll confirm any suspicions she has of you simply being a child.
You're not hurting her, their marriage was over for a while. Believe me, I know.