1) Do we have any historical sources on Sayida Khawla being the daughter of Imam Hussien (a.s.) also about her grave in present day Baalbak?

2) Also is the shrine in Syria really for sayida zainab?

1- We don’t have early sources that state Imam Hussain (a) had a daughter by the name Khawla. It is possible that one of the daughters of Imam Hussain (a) was buried there, and later people called her Khawla. It is also possible that she could be one of the granddaughters of Imam Hussain (a).

2- There are 3 opinions on where Lady Zaynab (a) is married: Syria, Medina, and Egypt. Most scholars believe she is buried in Syria.