Manually

First she had to check for any changes made to Laura's brain. For that, she simply inserted her finger into her ear, which resulted in a small shock for both of them. For Laura, it was of course caused by something entering her head, but for Sarah the shock came from not encountering any resistance at all. Her daughter's head was completely empty, there was no brain, just an empty skull filled with air. She tried searching deeper, pushing her whole hand inside, but still found nothing.

It was so surprising for her, who was well versed in a ways of science, to encounter something so impossible that she didn't stop probing Laura's head even when she started behaving strangely. Both her tits and pussy started gushing out their respective liquids, creating constant streams that pooled on the floor, her eyes were spinning rapidly in their sockets, and huge waves of pleasure were hitting her whole body, making her orgasm countless times per second.

She yanked her hand out, leaving Laura as a mewling mess on the floor and then went to her computer. Until now she wasn't sure if making a full backup of both hers and her daughter brains was a good idea, but seeing that one of them was permanently lost, she was glad she created them. She uploaded all of her daughter's data onto a pendrive, and then pondered how to install it.

After thinking a second, she decided to try using a bit of her blood on the drive, and when it was absorbed inside the inorganic structure, she knew she succeeded. She then proceeded to shove it into her daughter's head, making her cum again. Now all that was left was to wait for the drive to take the root. It wouldn't become a brain or fill her head completely, but it would restore her memories and for the most part, her personality. Leaving her literally empty-headed was a fun little addition.

The process took about five minutes to complete. When Laura "woke up" she was confused, her body different in a much sexier way. She was also very horny, feeling a need for something huge to fill her holes. She then saw her mother observing her, at which she came to conclusion that it was another of her experiments.

"What did you do to me?"

She was angry at her mother for changing her body like that, she wanted to protest, but her pussy stopped.

"I saved you from becoming a brainless bimbo when you got infested by a parasite and infected with a strange virus."

It then came back to her. Everything that happened after a strange worm crawled into her pussy, all the sex she committed, the guy whose head ended up in her asshole, and what her mother did to save her. She lifted her hand to her head and experimentally probed her ear with a single finger, making her shudder both in pleasure that hit her and the horror at not finding anything inside.

Suddenly, a different wave of pleasure hit her.

"Oh, it looks like I can control your body freely with my version of the virus."

She didn't know what her mother meant, but she fell to the floor again as she clutched her belly which was now emanating orgasmic bliss to her whole body. It slowly started inflating, pushing her hands away and quickly reaching the size a pregnant woman would have. It then grew more, and more, stretching her skin to the limit that didn't exist. Finally, when her belly was bigger than her, it stopped.

"Now I'll have some more subjects to research."