She had a hole in her heart as a result and longed to be a mother.
However, shortly after, she had a heart attack and died in prison.
She accepted because she desperately needed cash to care for her ill grandmother.

Valentin had planned to have Sasha simply meet with Nina, then leave Port Charles.
Sasha fled town for fear of being killed herself or her secret being unearthed.
Sasha felt horrible and apologized profusely to Nina, who wouldn’t listen to her.

However, over time, Nina was able to accept her apologies and eventually forgave her.
To this day, Nina and Sasha have a pseudo-mother-daughter relationship and look out for one another.
