story identification - Post-apocalyptic book where people can enhance or alter their appearance with animal qualities

I read this book probably 10 or 15 years ago. I remember it starting out with a young woman (I think) talking to a computer and altering her appearance in a mirror. I believe she was making subtle changes that were up-to-date with what was popular for the time and I believe the book explained that other people had chosen to make less subtle changes and go full-on were-animal.

The book follows her and her father who becomes a leader of a new civilization, when the main computer is hit by terrorists or something. They fall into the dark ages and have to resort to surviving like they did in the middle ages. It was very descriptive at one point as the woman was trying to figure out how they used to handle menstrual cycles without technology. I remember there was bad guy, and I believe he was were-tiger or panther man, but he wanted the girl. He started raiding the small settlements that had arose in the aftermath, and became like a warlord wreaking havok, pillaging, and raping. The girls boyfriend fought the last battle with him and lost his arm.

I'm pretty sure the book was written in the 1950s. I remember thinking that it was strangely accurate and advanced for when it was written. I have been trying to remember this book for the last 10 years because it was open-ended and I believe it was part of a series. I remember this book being one of the best I've ever read. It could make you clench your teeth, laugh and cry all at once. Can anyone help me find it?

Answer

There will be Dragons by John Ringo. (available on a Baen CD)

In the future there is no want, no war, no disease nor ill-timed death. The world is a paradise-and then, in a moment, it ends. The council that controls the Net falls out and goes to war. Everywhere people who have never known a moment of want or pain are left wondering how to survive. But scattered across the face of the earth are communities which have returned to the natural life of soil and small farm. In the village of Raven's Mill, Edmund Talbot, master smith and unassuming historian, finds that all the problems of the world are falling in his lap. Refugees are flooding in, bandits are roaming the woods, and his former lover and his only daughter struggle through the Fallen landscape. Enemies, new and old, gather like jackals around a wounded lion. But what the jackals do not know is that while old he may be, this lion is far from death. And hidden in the past is a mystery that has waited until this time to be revealed. You cross Edmund Talbot at your peril, for a smith is not "all" he once was. . . .

Relevant scenes:

Teenage girl body alteration:

"Well, you know that Marguerite's birthday party is coming up, right?"
"I'm not going to let you have a body-sculpt, Rachel," Daneh said lifting her chin and t'tching in negation. "We've been over this before."
"But Mommm!" the teenager whined. "My body is disgusting. I'm too fat. My boobs are huge and my butt is the size of Mount Evert! Pleeease!?"
"You're not too fat," the doctor said definitively. "Your body mass index is square in the center of the charts; your nannites wouldn't let it be anywhere else. And this . . . boyish look that is the current fad is not healthy, even for females who have been body sculpted. You can only pare away so far then you're into reserves. Your friend Marguerite is probably below seven percent body fat. That's not healthy. Barely so for a male and not for an unChanged female. And I'm not going to let you tinker with your DNA . . ."
"I know, Mom," Rachel said with an exasperated sigh. "But . . . I just look like a cow. I'm sorry, but that's how I feel."
"Okay, just this once," Daneh sighed. "And only for the party and only a bit. Stand up."
Rachel bounced off the bed and held out the hologram projector, a thumb-sized cube of crystal. "I was looking at some styles. Can I have Varian Vixen?"

Edmund( the girl's father) becomes leader of new community post war:

"We need a vote," Myron said. "Any other nominations? Edmund, do you accept?"
The smith looked at the ground and to the others. A weight appeared to settle on his shoulders and something old and hard seemed to be in his countenance. But when he looked up his face was clear.
"I do."
"Any other nominations? No. All in favor say aye."
"Aye!"
"Opposed?" There was silence. "Passed by acclamation, Mayor Edmund."

Woman starts mensurating after medical nanites fail

"Not from her . . . anus," Tom said. "The . . . the other part. I'm sorry if I'm being unclear, but this is my mother, okay?"

"Okay," Daneh answered. She wracked her brain for what might be wrong and there was something nagging at her. But for the life of her, the only thing that came to mind was some sort of internal injury. "Did she fall? Was she hit?"
"Not that I'm aware of," Tom said.
Daneh held her peace until they reached the sprawling farmyard, then hurried inside with Rachel at her heels.

They went upstairs to where Myron was standing outside the bedroom door, wringing his hands.
"Thank God you're here, Daneh," Myron said. "I . . . she's . . . I just can't take it. Please help her!"
"I'll see what I can do, Myron," Daneh answered, secretly fearful that there wouldn't be much she could do. Without nannites she was virtually helpless. She might know the inner workings of the human body, but fixing that body took tools she no longer possessed."