How do i write a letter of support for a family based greencard?

[Bettyjmorales]

My daughter-in-law is sponsoring her father to come to the USA. She is a US Citizen and is trying to get her father a green card. I have been asked to write a letter of support but am not sure of how to do that. I do not know what to say or how to word it. Apparently, my daughter-in-laws birth certificate showing that her father is her father is not enough evidence to prove family relationship, so letters of support and verification of relationship have been requested. Any help is greatly appreciated. Thank you so much,

Betty Morales

[immihelp]

I have never heard about such letter of support. People need to provide affidavits. However, you can provide that only if you have the personal knowledge of her birth to her father.