Need advice

Me and my husband got married a year ago in Prague. We were having a happy married life, until a few months ago. Apparently, my husband's mother was pregnant with a girl(whom ik)'s husband. Yeah, that guy basically cheated on his wife. My husband is very furious and kinda embarrassed too, that his mother is pregnant at the age of 56. But his mother did not abort the child. He kept it, but two weeks ago, his mother died as she couldn't handle the delivery. My husband is still traumatized and he still can't believe that his mother is dead. He also cannot accept that he has a small sister now. My best friend know about this and a few days ago, she approached me and asked that if you'll are not interested in the child, then can she adopt her, as she is infertile and she wants a child badly. What do you think should be done? Honestly I'm just so blank at this moment. Please i could really use some advice