Question Summary:
Is keeping name Muhammad Hasan khan and Fatima( khan or Zahra) suitable?

Question Detail:

 
I am excited to inform you that me and my wife are expecting a baby in around 6 month's time. Even though we do not know the gender, we have started thinking about its name.
In case its a boy, we are interested in the name Hasan as this was selected by Prophet (pbuh) himself for his grand son. Also, this name is scarce in our relatives. As my full name is Muhammad Shahbaz Khan, so my son's name accordingly will be Muhammad Hasan Khan.
Q1) Please confirm the appropriateness of this name as well as its spelling.
In case its a girl, we are interested in the names of Aisha, Zainab, and Fatima. If we opt for the name Fatima, then the full name can be 1) Fatima Khan (as per my family name), or 2) Fatima Zahra (as per name of Prophet's (saw) daughter).
Q2) Please confirm which second name is better (Khan or Zahra) in case of daughter.

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykumwa-rahmatullāhiwa-barakātuhu
The name Muhammad Hasan Khan is correct and also suitable for your son’s name. Likewise, the name Fatima with Khan or Zahra both are suitable.
Hasan: Means "handsome", derived from Arabic (hasuna) "to be beautiful, to be good"
Fatima: Means “Abstain”, derived from Arabic ( فطم) in other words “to abstain from shameful acts”
Literal meaning of Fatima is “Baby’s nurse”.
Zahra: Means “White; Flower”.
 
And Allah Ta’āla Knows Best
Zakir Husain
Student DarulIftaa
Michigan, U.S.A 
Checked and Approved by,
Mufti Ebrahim Desai.