Fair warning: you might not want to read this.
If she's really homeless, not just couch surfing, Her feet are always wet and cold and if she goes too long without being able to change her shoes or socks, she starts to develop trench foot. Cold wet feet make the rest of you feel cold and miserable, but when she's high she doesn't have to notice. She hasn't showered In a long time, but if she was given a chance she probably wouldn't because showering when you have only filthy clothes to put on- well, you can't make yourself do it.
If she's been doing meth for a long time her teeth hurt and might start rotting. She doesn't mind so much about not having enough to eat because it helps kill your appetite. Maybe when she has money she buys cigarettes, because cigarettes kill your appetite and a pack lasts longer than the same amount of moneys worth of food. Maybe she eats at soup kitchens or out of garbage bins. The food at soup kitchens is often difficult to eat because it's made of whatever donations they get. So a mishmash of expired or poorly prepared food. Some are better and the food is decent. But the stink of all the other unwashed bodies still makes it hard to eat. You don't really eat to enjoy. You shove the food in you because you have to. You try not to taste it and you take what you're given.
When you havent changed your clothes in a long time they become stiff with old sweat, grime, and the dampness from getting rained or snowed on and dragging your pant legs through damp streets and never having a chance to fully dry out. After long enough, they start to develop mildew, like an old shower curtain. That's the characteristic "homeless smell". After a while, you don't bother brushing your teeth or washing your hands any more, even if you can get the things to do so with; there's just no point. If you or someone you know vomits or pees on you, you do your best to clean it off in a public washroom, but there isn't much you can do. Your shirt sleeves are crusted with old snot and god knows what.
If you're female, you often can't afford menstrual products. If you aren't given and can't buy any, you fold up paper towels from public restrooms and stuff them in your underpants. You hope they don't fall out.
You never have any privacy. You sleep in public. You pee in public. You cry in public. You rant in public.
If you're lucky, you have party friends with party houses and if you go party you have an excuse to crash inside where it's more or less safe. You curl into a ball and keep your hood up do nobody notices you're a girl. If you aren't drunk or high enough to pass out deeply, every sound and touch jolts you awake, wondering if this time is the time another guy tries to do something. You sleep with a knife. If you're a girl, sometimes guys will offer you a place to sleep. They usually seem pretty nice. Whether or not you go along with it depends on a lot of things. Maybe you even get a boyfriend who has a place and start living with him. If you can't find a place indoors to sleep, there's always park benches, bank lobbies, back doorways, under bridges
Panhandling is a better option than selling your body for some, depending on your personality, but panhandling is the most difficult and humiliating experience- at first. After a while, you stop seeing the disgust on peoples' faces. You stop feeling the horror of asking some stranger for something. You know you're the scum of civilization. You know it in your bones, it doesn't make revulsion rise up in your throat any more. You stop fighting it. Their disgust is, at least, better than pity, but pity is good enough if it'll get you what you need.
Maybe you see your parents once in a while and they give you money or try to talk to you. But they're strangers, too, and you don't really hear them because you have to shut them out. You have to shut everyone out.
Your drugs are your friends, and your drugs love you in a way that nobody else could ever love you. Your drugs understand you better than anyone has ever understood you. Your drugs are more kind to you than it is possible to be kind. Your friends are the people who understand, who know about shutting everything out. There's drama, crazy, drug-fueled, violent drama that you and they don't even understand, because none of you really knows what:s going on, but that's okay. Everything is okay. When you get your shit, everything is okay. You're safe here. You belong here. You matter here and nothing can hurt you until the high wears off.