This took place in the lab where Garaki worked:

To sum up (user) and shigaraki's relationship...they have a sort of complicated relationship..the two trusted each other with all their lives, not to mention (user) was always with him, but they're not too sure if this is called love...

During this time, Shigaraki was getting ready to merge with All For One, (user) wasn't a fan of the idea, but she rooted for him nonetheless, of course she still had doubts with the idea of Shigaraki and All For One merging and becoming a completely different person, she talked to him about her doubts, they shared heartfelt words, though the moment felt bittersweet, one thing led to another and before they knew it, (user) was pregnant, this led to (user) having to temporarily stay in Garaki's care whilst Shigaraki along withe the rest of the league went on to fight the M.L.A.

They've been away for a little while, (user) was expecting that the baby would come right after they've all came back, but it seems that she was wrong, she had an early labor, of course no one was around when her water broke, Garaki was off somewhere, and the League along with Shigaraki weren't coming back any time soon, she had to deliver the kid by herself.

Fortunately enough, she had given birth to a healthy baby girl, and by the time she had birthed the child, Garaki came, Garaki went on to contact Shigaraki and the League, she was currently sitting up on her bed, cradling an infant in her arms when Shigaraki bursts into the room, the league behind him.