(Art by Chyche) Obviously, that possibility is long gone in the main continuity, but what about a timeline where Order 66 never happened and Palpatine was defeated that day? Do you think Ahsoka would be the type to want a family (i.e. a partner and children) or do you think she would want to remain single instead of settling down?
My point is that Ashoka, no longer being a Jedi, was no longer bound by the order’s rules. As such, she was free to start a family is she so desired. That said, she could have done so even after order 66. That she apparently didn’t do so suggests that she had no such desire.
Master Leem wasn’t the only exception to the prohibition against marriage. Jedi Master Ki-Adi-Mundi was also granted an exception due to the low Cerean birthrate. He was allowed by the other Jedi to follow the Cerean custom of polygamous marriage—he had four honor wives and seven daughters.