what is the definition of Ahl ul Bayt

Re: what is the definition of Ahl ul Bayt

Daughters of the prophet SAW were

1. Sayyidatina Fatima (18 B.H-11 A.H)

 **2. Sayyidatina Zaynab (23 B.H-8 A.H)**

 **3. Sayyidatina Ruqayya (20 B.H-2 A.H)**

 **4. Sayyidatina Umm Kulthum (19 B.H-9 A.H),**

may Allah be pleased with them all.

Wives of the Prophet SAW

1. Khadijah bint Khuwaylid
**
**2. Sawada bint Zam'a

**
3. A'isha Siddiqa bint Abu Bakr
**
4.Hafsa bint 'Umar
**
5. Zaynab bint Khuzayma
**
6.Umm Salama Hind bint Abi Umayya
**
7. Zaynab bint Jahsh
**
8.Juwayriya bint al-Harith
**
9. Umm Habiba Ramla bint Abi Sufyan
**
10. Safiyya bint Huyayy
**
11. Maymuna bint al-Harith
**
12. Maria al-Qibtiyya

AND

Sons of the Prophet SAW**
1- Abd-Allah ibn Muhammad

2- Qasim ibn Muhammad

3- Ibrahim ibn Muhammad
**

Correct me if I am wrong in my list here.

My question is:

How come all of these are not considered 'family members' of the Prophet SAW?