The Workaholic Down the Hall by Katharine Sadler

One night. One night to forget all the reasons why not and give in to an attraction that had been brewing for years between Aubrey Fletcher and her best friend and boss, Noah Reynolds.

One night that Noah doesn’t even remember. A drunken encounter that Aubrey can never forget, and she couldn’t go to work every day and face Noah. So, she cut herself out of his life, found a new job, and built a new life without him in it.
Except that after she left, she found out she was pregnant with Noah’s child.
Noah refuses to talk to his former best friend, because she disappeared without a word of explanation, and Aubrey reveals her secret to his mother, Nora.

Nora wants to be a part of her grandbaby’s life, but she also wants Noah and Aubrey to admit what she’s seen all along – that they’d be perfect for each other. Nora will go to any lengths, no matter how potentially illegal, to see Aubrey and Noah parenting her grandbaby as a couple.