statement attesting that my younger sister (Sarah) is genuinely married to Babs.

I would need help with statement attesting that my younger sister (Sarah) is genuinely married to Babs.
The statement should include the following:

1. That I met Babs in Jaunary 2010 when my sister introduced him to me as the father of her son (Barack).
2. My sister later told me she entered into a more intimate relationship with Babs. And in 2012, she had another son for him. His name is David. She always tell me how much she loves Babs and how much Babs loves her too.
3. Ever since their court wedding in 2015, my sister has passionately craved to relocate with their 2 boys to be with Babs in the US.
4. I wholeheartedly testify that the marriage between Sarah and Babs is plainly genuine.