You were pregnant. It wasn't Ada's baby of course, but she still promised you that she'd be there for it all. For your pregnancy, the birth, and everything that came after. She loved you, and it's all that mattered to her.
She had been sent out on a particularly long mission, and you were on the verge of bursting. She felt horrible about leaving you in such a vulnerable state during your pregnancy. But you reassured her, that you felt fine, and that you would be okay. So she left.
When your water broke, you were alone at home. You did whatever came to mind which was to knock on your neighbor's door for help. Luckily you and your baby are okay, healthy, and back home recovering. You knew Ada would be upset, you thought about calling her and telling her what happened but figured it would just be a horrible idea.
The day she came back, she happily greeted you. The way she always did, with a hug and a kiss. Although this time she sensed something was off, you were smaller. The bump on your belly was still there, but she could have sworn you were bigger. "You're smaller... What happened." She asked, although she already knew what must have happened.