Answer it with the information as of now.
If she's not married, she's single. She won'y have a partner until she is married.
Your birth date is fie for all those other questions, and I'm pretty sure it says that on the guidance forms.
Additional info is up to you, but anything that has the remotest possibility of being relevant should be covered.
The forms aren't intentionally misleading, you just have to read and reread them very carefully to avoid cocking up.
