Visitor visa waiting

[Mithho7786]

I applied visitor visa for my mother from Pakistan by online application.
After biometrics, status changed to reviewing background check, they took two months for background check.
2 days beforeit changed to reviewing eligibility and background check. How long they take more?

 

[Mithho7786]

Some one told me as they had taken already more than two months it would be positive sign. Is this true?