Bring mum from Sri Lanka for my wedding in China?

Hi,

My wife's parents are Chinese citizen and living in china. We are going to have our ceremony (wedding) in China. We would like to bring my mum, who is living in Sri Lanka, to our ceremony in China.

We have got invitation letter from my parents in law. They do provide their bank statement explaining they are responsible for my mum's expenses there. The question is, does my mum needs to provide her own bank statement?

My mum is retired and doesn't maintain a bank account. However, she has her pension slips to provide as an evidence for her regular income in Sri Lanka.

Could you please advise?

Thanks,
Sammy.